I am trying to make a very basic "secret santa" generator as one of my first Javascript projects. I have searched for hours for a solution to this problem but so far nothing has worked that I have found.
I have an array of names which need paired to each other. I successfully have them pairing to each other, but right now someone can be drawn twice. I am pushing the randomly chosen names to another array but I can't find a way to check the randomly chosen names against the ones already chosen.
var names = ["Sean","Kyle","Emily","Nick","Cotter","Brian","Jeremy","Kimmy","Pat","Johnny"];
var used = [];
var picks = [];
if (names.length % 2 != 0) {
alert("You must have an even number of names. You currently have " + names.length + " names.");
}
for( var i = 0; i < names.length; i++){
var random = Math.floor(Math.random()*names.length)
if(names[random] == names[i]) {
names[random] = names[random++];
picks.push(names[i] + " gets " + names[random]);
used.push(names[random]);
} else {
picks.push(names[i] + " gets " + names[random]);
used.push(names[random]);
}
}
console.log("picked array: ")
for(var k=0; k<picks.length; k++) {
console.log(picks[k]);
}
console.log("used array: " + used);
Thank you in advance for any help.
Create two arrays with the names, shuffle them, and make sure you don't pick the same name from both arrays :
var names = ["Sean","Kyle","Emily","Nick","Cotter","Brian","Jeremy","Kimmy","Pat","Johnny"];
if (names.length % 2 != 0) {
alert("You must have an even number of names. You currently have " + names.length + " names.");
} else {
var arr1 = names.slice(), // copy array
arr2 = names.slice(); // copy array again
arr1.sort(function() { return 0.5 - Math.random();}); // shuffle arrays
arr2.sort(function() { return 0.5 - Math.random();});
while (arr1.length) {
var name1 = arr1.pop(), // get the last value of arr1
name2 = arr2[0] == name1 ? arr2.pop() : arr2.shift();
// ^^ if the first value is the same as name1,
// get the last value, otherwise get the first
console.log(name1 + ' gets ' + name2);
}
}
FIDDLE
I would suggest a different approach. Shuffle, split, and zip, no mutation:
var splitAt = function(i, xs) {
var a = xs.slice(0, i);
var b = xs.slice(i, xs.length);
return [a, b];
};
var shuffle = function(xs) {
return xs.slice(0).sort(function() {
return .5 - Math.random();
});
};
var zip = function(xs) {
return xs[0].map(function(_,i) {
return xs.map(function(x) {
return x[i];
});
});
}
// Obviously assumes even array
var result = zip(splitAt(names.length/2, shuffle(names)));
//^
// [
// [ 'Nick', 'Kimmy' ],
// [ 'Sean', 'Johnny' ],
// [ 'Kyle', 'Brian' ],
// [ 'Cotter', 'Pat' ],
// [ 'Emily', 'Jeremy' ]
// ]
There is a multitude of ways you can achieve this.
The fastest to code, but not necessarily the randomest is:
var names = ["Sean","Kyle","Emily","Nick","Cotter","Brian","Jeremy","Kimmy","Pat","Johnny"];
function getPicks(names) {
return names.slice(0).sort(function(){ return Math.random()-0.5 }).map(function(name, index, arr){
return name + " gets " + arr[(index+1)%arr.length];
});
}
getPicks(names);
This is not very random because the shuffling isn't very good and also because you get a single cycle each time. There can be no two cycles A->B->C->A D->E->D.
If you want it to have a random number of cycles of variable length, you can split the names array in several arrays and do the above for each of them, then concatenate the results (see elclanrs).
Finally, the last solution is for each person to pick a person at random and if it's the same one, simply pick again. If the last name remaining in both arrays is the same, simply swap it with another pair.
var names = ["Sean","Kyle","Emily","Nick","Cotter","Brian","Jeremy","Kimmy","Pat","Johnny"];
var a = names.slice(0);
var b = names.slice(0);
var result = [];
while (a.length > 1) {
var i = extractRandomElement(a);
var j = extractRandomElement(b);
while (i===j) {
b.push(j);
j = extractRandomElement(b);
}
result.push({ a:i, b:j });
}
if (a[0] === b[0]) {
result.push({ a:a[0], b:result[0].b });
result[0].b = a[0];
} else {
result.push({ a:a[0], b:b[0] });
}
var pairs = result.map(function(item){ return item.a + ' gets ' + item.b});
function extractRandomElement(array) {
return array.splice(Math.floor(Math.random()*array.length),1)[0];
}
I'm a tad late, but thought I'd throw my answer in here. It essentially does the same thing #adeneo's does, but it uses the same basic code as OP:
var names = ["Sean","Kyle","Emily","Nick","Cotter","Brian","Jeremy","Kimmy","Pat","Johnny"];
pickpool = names.slice(0); // Slice the array at the first element to copy it by value
var used = [];
var picks = [];
if (names.length % 2 != 0) {
alert("You must have an even number of names. You currently have " + names.length + " names.");
}
for( var i = 0; i < names.length; i++){
var random = Math.floor(Math.random()*pickpool.length)
if(names[random] == names[i]) {
// names[random] = names[random++];
picks.push(names[i] + " gets " + pickpool[random++]);
pickpool.splice(random++,1);
} else {
picks.push(names[i] + " gets " + pickpool[random]);
pickpool.splice(random,1);
}
}
console.log("picked array: ");
for(var k=0; k<picks.length; k++) {
console.log(picks[k]);
}
http://jsfiddle.net/SNJpC/
If you don't need to keep the original array you can remove the names as they get selected and each time you pick a name check that it isn't an empty string before pushing it to the next array.
Another consideration...
If you are trying to make a 'Secret Santa' generator, by using random method you can get the same pair next year, and next...
This is another solution where you get all the possible pairs (without repeating a name itself or a pair) for multiple years.
var names = ["Sean", "Kyle", "Emily", "Nick", "Cotter", "Brian", "Jeremy", "Kimmy", "Pat", "Johnny"];
if (names.length % 2 != 0) {
alert("You must have an even number of names. You currently have " + names.length + " names.");
} else {
const arr1 = names.slice()
let arr2 = names.slice();
let countDown = number => {
if (number === 1) {
return;
}
const last = arr2.pop([number - 1]);
arr2.unshift(last);
let pairs = [];
arr1.map(item => {
const index = arr1.indexOf(item);
pairs.push(`${arr1[index]} gets ${arr2[index]}`)
})
console.log(pairs)
return countDown(number - 1);
}
countDown(names.length)
}
Related
Hi my knowledge on javascript is very limited and basic. Basically below is I will prompt a pop-up that displays the answer to the value. The thing is from the coding I found below if I had to insert an array lets say 1,2,3,2 the output would be , since it has the highest occurrence in the array. Is there a way to edit this code so that the answer to the input above would be 2
I have done my fair share of research:
Here are the links:
Highest occurrence in an array or first selected
Get the element with the highest occurrence in an array
https://www.sitepoint.com/community/t/numbers-only-input-values-in-text-box-how/3029
Code:
<script type="text/javascript">
function evaluate() {
var input = prompt("Please enter your input");
var array = new Array();
function mode(array)
{
if(array.length == 0)
return null;
var modeMap = {};
var maxEl = array[0], maxCount = 1;
for(var i = 0; i < array.length; i++)
{
var el = array[i];
if(modeMap[el] == null)
modeMap[el] = 1;
else
modeMap[el]++;
if(modeMap[el] > maxCount)
{
maxEl = el;
maxCount = modeMap[el];
}
}
return maxEl;
}
document.writeln("Your calculation is: ");
document.writeln(mode(input) + " with a starting input string of: " + input);
}
</script>
<script type="text/javascript">
evaluate();
</script>
You want to convert the string '1,2,3,2' into the array [ 1, 2, 3, 2 ] first. this can be done with the split function. You probably also want to trim each element in case someone formats them with a space.
function evaluate() {
const input = prompt("Please enter the array of integers")
.split(',')
.map(item => item.trim());
function mode(items) {
const counts = items
.reduce((counts, item) => {
const currentItemCount = counts.get(item) || 0;
return counts.set(item, currentItemCount + 1);
}, new Map());
const maxEntry = Array.from(counts.entries())
.reduce((maxEntry, entry) => {
return entry[1] > maxEntry[1] ? entry : maxEntry;
});
return maxEntry[0];
}
document.writeln("Your calculation is: ");
document.writeln(mode(input) + " with a starting input string of: " + input);
}
evaluate();
Your issue stems from the fact that you never convert your input (which you receive from prompt as a string) into an actual array.
When mode is called directly on the string, the comma is returned as being the most common because comma is the most common character in the string.
To fix this, you need to convert your string into an actual array so you're operating on the elements of the array instead of the characters of the string.
You can use the split function to split your string ("1,2,3,2") at commas into an array (["1", "2", "3", "2"]) which you can then pass to the mode function:
mode(input.split(","))
So i have this array
[ 'vendor/angular/angular.min.js',
'vendor/angular-nice-bar/dist/js/angular-nice-bar.min.js',
'vendor/angular-material/modules/js/core/core.min.js',
'vendor/angular-material/modules/js/backdrop/backdrop.min.js',
'vendor/angular-material/modules/js/dialog/dialog.min.js',
'vendor/angular-material/modules/js/button/button.min.js',
'vendor/angular-material/modules/js/icon/icon.min.js',
'vendor/angular-material/modules/js/tabs/tabs.min.js',
'vendor/angular-material/modules/js/content/content.min.js',
'vendor/angular-material/modules/js/toolbar/toolbar.min.js',
'vendor/angular-material/modules/js/input/input.min.js',
'vendor/angular-material/modules/js/divider/divider.min.js',
'vendor/angular-material/modules/js/menu/menu.min.js',
'vendor/angular-material/modules/js/select/select.min.js',
'vendor/angular-material/modules/js/radioButton/radioButton.min.js',
'vendor/angular-material/modules/js/checkbox/checkbox.min.js',
'vendor/angular-material/modules/js/switch/switch.min.js',
'vendor/angular-material/modules/js/tooltip/tooltip.min.js',
'vendor/angular-material/modules/js/toast/toast.min.js',
'vendor/angular-clipboard/angular-clipboard.js',
'vendor/angular-animate/angular-animate.min.js',
'vendor/angular-aria/angular-aria.min.js',
'vendor/angular-messages/angular-messages.min.js',
'vendor/angular-ui-router/release/angular-ui-router.js',
'src/app/about/about.js',
'src/app/hekate.cfg.js',
'src/app/hekate.ctrl.js',
'src/app/hekate.module.js',
'src/app/home/home.js',
'src/app/user/dialog/user.signIn.ctrl.js',
'src/app/user/dialog/user.signIn.module.js',
'src/app/user/user.cfg.js',
'src/app/user/user.ctrl.js',
'src/app/user/user.module.js',
'src/common/services/toast.service.js',
'templates-common.js',
'templates-app.js'
]
And taking the following part from the above array as example:
[
'src/app/hekate.cfg.js',
'src/app/hekate.ctrl.js',
'src/app/hekate.module.js',
]
I want to sort it like
[
'src/app/hekate.module.js',
'src/app/hekate.cfg.js',
'src/app/hekate.ctrl.js',
]
So more specific of what i want is to find in that array where string is duplicated and after check if has at the end [.cfg.js, .ctrl.js, .module.js] and automatic order them to [.module.js, .cfg.js, .ctrl.js]
Can anyone please help me with that?
A single sort proposal.
var array = ['src/app/about/about.js', 'src/app/hekate.cfg.js', 'src/app/hekate.ctrl.js', 'src/app/hekate.module.js', 'src/app/home/home.js', 'src/app/user/dialog/user.signIn.ctrl.js', 'src/app/user/dialog/user.signIn.module.js', 'src/app/user/user.cfg.js', 'src/app/user/user.ctrl.js', 'src/app/user/user.module.js'];
array.sort(function (a, b) {
function replaceCB(r, a, i) { return r.replace(a, i); }
var replace = ['.module.js', '.cfg.js', '.ctrl.js'];
return replace.reduce(replaceCB, a).localeCompare(replace.reduce(replaceCB, b));
});
document.write('<pre>' + JSON.stringify(array, 0, 4) + '</pre>');
To prevent so much replaces, i suggest to have a look to sorting with map.
You can try something like this:
Algo:
Group based on path and store file names as value.
Check for existence of one of special file ".cfg.js"
Sort following list based on custom sort.
Loop over object's property and join key with values to form full path again.
If you wish to sort full array, you can sort keys itself and then merge path with names. I have done this. If you do not wish to do this, just remove sort function from final loop.
Sample
var data=["vendor/angular/angular.min.js","vendor/angular-nice-bar/dist/js/angular-nice-bar.min.js","vendor/angular-material/modules/js/core/core.min.js","vendor/angular-material/modules/js/backdrop/backdrop.min.js","vendor/angular-material/modules/js/dialog/dialog.min.js","vendor/angular-material/modules/js/button/button.min.js","vendor/angular-material/modules/js/icon/icon.min.js","vendor/angular-material/modules/js/tabs/tabs.min.js","vendor/angular-material/modules/js/content/content.min.js","vendor/angular-material/modules/js/toolbar/toolbar.min.js","vendor/angular-material/modules/js/input/input.min.js","vendor/angular-material/modules/js/divider/divider.min.js","vendor/angular-material/modules/js/menu/menu.min.js","vendor/angular-material/modules/js/select/select.min.js","vendor/angular-material/modules/js/radioButton/radioButton.min.js","vendor/angular-material/modules/js/checkbox/checkbox.min.js","vendor/angular-material/modules/js/switch/switch.min.js","vendor/angular-material/modules/js/tooltip/tooltip.min.js","vendor/angular-material/modules/js/toast/toast.min.js","vendor/angular-clipboard/angular-clipboard.js","vendor/angular-animate/angular-animate.min.js","vendor/angular-aria/angular-aria.min.js","vendor/angular-messages/angular-messages.min.js","vendor/angular-ui-router/release/angular-ui-router.js","src/app/about/about.js","src/app/hekate.cfg.js","src/app/hekate.ctrl.js","src/app/hekate.module.js","src/app/home/home.js","src/app/user/dialog/user.signIn.ctrl.js","src/app/user/dialog/user.signIn.module.js","src/app/user/user.cfg.js","src/app/user/user.ctrl.js","src/app/user/user.module.js","src/common/services/toast.service.js","templates-common.js","templates-app.js"];
// Create groups based on path
var o = {};
data.forEach(function(item) {
var lastIndex = item.lastIndexOf('/') + 1;
var path = item.substring(0, lastIndex);
var fname = item.substring(lastIndex);
if (!o[path]) o[path] = [];
o[path].push(fname);
});
var manualOrder= [".module.js", ".cfg.js", ".ctrl.js"];
Array.prototype.fuzzyMatch = function(search){
return this.some(function(item){
return item.indexOf(search)>-1;
});
}
Array.prototype.fuzzySearchIndex = function(search){
var pos = -1;
this.forEach(function(item, index){
if(search.indexOf(item)>-1){
pos = index;
}
});
return pos;
}
function myCustomSort(a,b){
var a_pos = manualOrder.fuzzySearchIndex(a);
var b_pos = manualOrder.fuzzySearchIndex(b);
return a_pos > b_pos ? 1 : a_pos < b_pos ? -1 : 0;
}
// Check for ".cfg.js" and apply custom sort
for (var k in o) {
if (o[k].fuzzyMatch(".cfg.js")) {
o[k].sort(myCustomSort);
}
}
// Merge Path and names to create final value
var final = [];
Object.keys(o).sort().forEach(function(item) {
if (Array.isArray(o[item])) {
final = final.concat(o[item].map(function(fn) {
return item + fn
}));
} else
final = final.concat(o[item]);
});
console.log(final);
First make an array for names like 'hekate'.
Then make an array for final results.
We need 3 searching loops for ctrls, cfgs and modules.
If string contains arrayWithNames[0] + '.module' push the whole record to new array that you created. Same with ctrls and cfgs.
var allItems = []; //your array with all elements
var namesArray = [];
var finalResultsArray = [];
//fill name array here:
for(var i=0; i<=allItems.length; i++){
//you have to split string and find the module name (like 'hekate'). i hope you know how to split strings
}
//sort by modules, cfgs, ctrls:
for(var i=0; i<=namesArray.length; i++){
if(allItems[i].indexOf(namesArray[i] + '.module') > -1) {
finalResultsArray.push(allItems[i]);
}
}
for(var i=0; i<=namesArray.length; i++){
if(allItems[i].indexOf(namesArray[i] + '.cfg') > -1) {
finalResultsArray.push(allItems[i]);
}
}
for(var i=0; i<=namesArray.length; i++){
if(allItems[i].indexOf(namesArray[i] + '.ctrl') > -1) {
finalResultsArray.push(allItems[i]);
}
}
//now finalResultsArray have what you wanted
You can provide your own compare function to array.sort (see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort)
Write one that returns the correct order for modules, ctrls and cfgs:
It should first remove the suffixes, and if the rest is the same, use the correct logic to return the order according to the suffix. Otherwise return a value according to the alphabetical order.
Update
I didn't test this code (not is it finished), but it should look something like that:
arr.sort(function(a, b) {
if ((a.endsWith(".cfg.js") || a.endsWith(".ctrl.js") || a.endsWith(".module.js")) &&
(b.endsWith(".cfg.js") || b.endsWith(".ctrl.js") || b.endsWith(".module.js"))) {
var sortedSuffixes = {
".module.js": 0,
".cfg.js": 1,
".ctrl.js": 2
};
var suffixAIdx = a.lastIndexOf(".cfg.js");
if (suffixAIdx < 0) suffixAIdx = a.lastIndexOf(".ctrl.js");
if (suffixAIdx < 0) suffixAIdx = a.lastIndexOf(".module.js");
var suffixBIdx = b.lastIndexOf(".cfg.js");
if (suffixBIdx < 0) suffixBIdx = b.lastIndexOf(".ctrl.js");
if (suffixBIdx < 0) suffixBIdx = b.lastIndexOf(".module.js");
var prefixA = a.substring(0, suffixAIdx);
var prefixB = b.substring(0, suffixAIdx);
if (prefixA != prefixB)
{
return a.localeCompare(b);
}
var suffixA = a.substring(suffixAIdx);
var suffixB = b.substring(suffixBIdx);
return sortedSuffixes[suffixA] - sortedSuffixes[suffixB];
} else {
return a.localeCompare(b);
}
});
Update 2
Here is a fiddle (https://jsfiddle.net/d4fmc7ue/) that works.
I have a JSON string of the form:
[
{"ID":153,"CircuitID":53,"StartTime":"2014-11-12 12:45:00","EventFormatID":224,"TotalPlaces":8,"BookedPlaces":0,"ProvisionalPlaces":0},
{"ID":161,"CircuitID":53,"StartTime":"2014-11-12 17:15:00","EventFormatID":224,"TotalPlaces":0,"BookedPlaces":0,"ProvisionalPlaces":0},
{"ID":734,"CircuitID":53,"StartTime":"2014-11-12 18:30:00","EventFormatID":231,"TotalPlaces":14,"BookedPlaces":0,"ProvisionalPlaces":0}
]
In place of Event Format ID and Circuit ID I will be returning the names
What I need to do is group the results by Event Format ID and return the results in the following format:
Event 224 : 12:45 (8 places available), 17:15 (0 places available)
Event 231 : 18:30 (14 places available)
I can't seem to figure out how to loop through the data, group it by Event Format ID to present it in the required format!
Thanks
Can you use any additional libraries? I'd use lo-dash which would make this relatively simple:
var grouped = _.groupBy(data, "EventFormatID");
_(grouped).forEach(function (group, key) {
console.log("Event:" + key);
_(group).forEach(function (course) {
console.log(course.StartTime + " (" + course.TotalPlaces + " places available)");
});
});
Obviously the example above logs to the console but it'd be fairly simple to change to build up whatever string or object you need.
This is easier with lodash/underscore, or even with ES5 array and object methods, but since you asked about pure JS:
var data = {}, results = [], i, j, id, time, obj, evts; // obj is your object above
for (i=0; i<obj.length; i++) {
id = obj[i].EventFormatID;
time = obj[i].StartTime; // you can simplify to get just the time, not the datetime, if you prefer
data[id] = data[id] || [];
data[id].push({"time":time,"places":obj[i].TotalPlaces});
}
// now you have a proper data structure, just print it out
for (i in data) {
if (data.hasOwnProperty(i)) {
// just show the output properly formatted
evts = [];
for (j=0;i<data[i].length;j++) {
evts.push(data[i][j].time+" ("+data[i][j].places+" places available)");
}
results.push("Event "+i+" : "+evts.join(","));
}
}
ES5 makes this so much easier
var data = {}, results = [], obj; // obj is your object above
obj.forEach(function(val,i) {
data[val.EventFormatID] = data[val.EventFormatID] || [];
data[val.EventFormatID].push({"time":val.StartTime,"places":val.TotalPlaces});
});
// now you have a proper data structure, just print it out
Object.keys(data).forEach(function(key) {
var value = data[key], evts = [];
value.forEach(function(elm) {
evts.push(elm.time+" ("+elm.places+" places available)");
});
results.push("Event "+key+" : "+evts.join(","));
});
And lodash is even easier.
Please take a look that:
http://jsfiddle.net/m260n5ud/
html
<div id="contentDiv"></div>
js
function tidyUp(jsonArray) {
var myObject = {};
for (i = 0; i < jsonArray.length; i++) {
var key = jsonArray[i]['EventFormatID'];
var time = jsonArray[i]['StartTime'].replace(' ', ':').split(/[- :]/);
time = time[3] + ":" + time[4];
var totalPlace = jsonArray[i]['TotalPlaces'];
if (myObject[key] == null) {
myObject[key] = "Event : " + key + " : " + time + " ( " + totalPlace + " places available)";
} else {
myObject[key] += ", " + time + " ( " + totalPlace + " places available)";
}
}
console.log(myObject);
for (var k in myObject) {
document.getElementById('contentDiv').innerHTML += myObject[k] + "<br/>";
}
}
I have a multi-dimensional array. I need some sort of loop to randomly pick a string in the array and check to see if that string contains a character. If it doesn't, then repeat until it finds one.
I wrote a for loop that checks the array for the string, BUT it starts from 0 and works its way through the array until it finds it. I need it randomly pick a string in the array...any help?
jsFiddle --> http://jsfiddle.net/hz2MZ/1/
jQuery
$(document).ready(function() {
var myarr = [{"Name":"Bob", "Char":"134"},
{"Name":"Phil", "Char":"134"},
{"Name":"Jane", "Char":"1"},
{"Name":"Don", "Char":"4"},
{"Name":"Dan", "Char":"2"},
{"Name":"Jan", "Char":"12"},
{"Name":"Bill", "Char":"24"},
{"Name":"Sam", "Char":"14"},
{"Name":"Jake", "Char":"23"},
{"Name":"Ben", "Char":"3"}];
$('button').click(function() {
for(var i = 0; i < myarr.length; i++) {
if(myarr[i].Char.indexOf('2') !== -1) {
alert("Name: " + myarr[i].Name + "\nChar: " + myarr[i].Char);
return;
} else {}
}
});
});
My solution
$('button').click(function () {
var found = false;
while (!found) {
var randomIndex = Math.floor(Math.random() * myarr.length);
if (myarr[randomIndex].Char.indexOf('2') !== -1) {
alert("Name: " + myarr[randomIndex].Name + "\nChar: " + myarr[randomIndex].Char);
found = true;
} else {}
}
});
edit
Updated endless loop problem
$('button').click(function () {
var found = false;
var maxRandom = 20;
var currentRandom = 0;
while (!found && currentRandom < maxRandom) {
var randomIndex = Math.floor((Math.random() * myarr.length));
currentRandom++;
if (myarr[randomIndex].Char.indexOf('2') !== -1) {
alert("Name: " + myarr[randomIndex].Name + "\nChar: " + myarr[randomIndex].Char);
found = true;
} else {}
}
}
One approach is to copy the array, then randomly splice one member from the copy and check for the required value:
function randomValueByChar(arr, c) {
var a = arr.slice && arr.slice();
var i = a.length || 0;
var t;
while (i--) {
t = a.splice(Math.random() * i | 0, 1);
if (t[0].Char.indexOf(c) != -1) return t;
}
}
Another approach is to create an array of the indexes (e.g. [0,1,2,3…]), then randomly splice one value at a time and use it as an index to retrieve a value from the array. Both approaches will not have an infinite loop and will visit each member a maximum of once.
What's the best and most efficient way to count keywords in JavaScript? Basically, I'd like to take a string and get the top N words or phrases that occur in the string, mainly for the use of suggesting tags. I'm looking more for conceptual hints or links to real-life examples than actual code, but I certainly wouldn't mind if you'd like to share code as well. If there are particular functions that would help, I'd also appreciate that.
Right now I think I'm at using the split() function to separate the string by spaces and then cleaning punctuation out with a regular expression. I'd also want it to be case-insensitive.
Cut, paste + execute demo:
var text = "Text to be examined to determine which n words are used the most";
// Find 'em!
var wordRegExp = /\w+(?:'\w{1,2})?/g;
var words = {};
var matches;
while ((matches = wordRegExp.exec(text)) != null)
{
var word = matches[0].toLowerCase();
if (typeof words[word] == "undefined")
{
words[word] = 1;
}
else
{
words[word]++;
}
}
// Sort 'em!
var wordList = [];
for (var word in words)
{
if (words.hasOwnProperty(word))
{
wordList.push([word, words[word]]);
}
}
wordList.sort(function(a, b) { return b[1] - a[1]; });
// Come back any time, straaanger!
var n = 10;
var message = ["The top " + n + " words are:"];
for (var i = 0; i < n; i++)
{
message.push(wordList[i][0] + " - " + wordList[i][1] + " occurance" +
(wordList[i][1] == 1 ? "" : "s"));
}
alert(message.join("\n"));
Reusable function:
function getTopNWords(text, n)
{
var wordRegExp = /\w+(?:'\w{1,2})?/g;
var words = {};
var matches;
while ((matches = wordRegExp.exec(text)) != null)
{
var word = matches[0].toLowerCase();
if (typeof words[word] == "undefined")
{
words[word] = 1;
}
else
{
words[word]++;
}
}
var wordList = [];
for (var word in words)
{
if (words.hasOwnProperty(word))
{
wordList.push([word, words[word]]);
}
}
wordList.sort(function(a, b) { return b[1] - a[1]; });
var topWords = [];
for (var i = 0; i < n; i++)
{
topWords.push(wordList[i][0]);
}
return topWords;
}
Once you have that array of words cleaned up, and let's say you call it wordArray:
var keywordRegistry = {};
for(var i = 0; i < wordArray.length; i++) {
if(keywordRegistry.hasOwnProperty(wordArray[i]) == false) {
keywordRegistry[wordArray[i]] = 0;
}
keywordRegistry[wordArray[i]] = keywordRegistry[wordArray[i]] + 1;
}
// now keywordRegistry will have, as properties, all of the
// words in your word array with their respective counts
// this will alert (choose something better than alert) all words and their counts
for(var keyword in keywordRegistry) {
alert("The keyword '" + keyword + "' occurred " + keywordRegistry[keyword] + " times");
}
That should give you the basics of doing this part of the work.
Try to split you string on words and count the resulting words, then sort on the counts.
This builds upon a previous answer by insin by only having one loop:
function top_words(text, n) {
// Split text on non word characters
var words = text.toLowerCase().split(/\W+/)
var positions = new Array()
var word_counts = new Array()
for (var i=0; i<words.length; i++) {
var word = words[i]
if (!word) {
continue
}
if (typeof positions[word] == 'undefined') {
positions[word] = word_counts.length
word_counts.push([word, 1])
} else {
word_counts[positions[word]][1]++
}
}
// Put most frequent words at the beginning.
word_counts.sort(function (a, b) {return b[1] - a[1]})
// Return the first n items
return word_counts.slice(0, n)
}
// Let's see if it works.
var text = "Words in here are repeated. Are repeated, repeated!"
alert(top_words(text, 3))
The result of the example is: [['repeated',3], ['are',2], ['words', 1]]
I would do exactly what you have mentioned above to isolate each word. I would then probably add each word as the index of an array with the number of occurrences as the value.
For example:
var a = new Array;
a[word] = a[word]?a[word]+1:1;
Now you know how many unique words there are (a.length) and how many occurrences of each word existed (a[word]).