I have a string and I wanna create an array with even occurrence of "[]"
"Match[0][a][5][b][0][d][2]"
I want to split them and make an array using this string on the basis of instance of "[]". Each element of the array must have 2 occurrence of "[]" and the next element has two more occurrence of"[]". In another words I wanna create an array with even occurrence of "[]"
I want to make an array from string like:
["Match[0]['a']", "Match[0]['a'][5]['b']", "Match[0]['a'][5]['b'][0]['d']"]
Using javascript/jQuery
I have tried match but I only got it as far as this.
// ['part1.abc', 'part2.abc', 'part3.abc', 'part4']
'part1.abc.part2.abc.part3.abc.part4'.match(/[^.]+(\.[^.]+)?/g);
You can get the individual pieces in your array and then manipulate the result until it has the form you want. An example could be this one:
var str = "Match[0][a][5][b][0][d][2]";
var result = [];
str.split(/[\]\[]{1,2}/).slice(0,-1).reduce(function(acc,item, index) {
acc += '[' + (isNaN(item) ? "'" + item + "'" : item) + ']';
if (index %2 === 0 && index !== 0) {
result.push(acc);
}
return acc;
});
console.log(result) // ["Match[0]['a']", "Match[0]['a'][5]['b']", "Match[0]['a'][5]['b'][0]['d']"]
You can get each bracket with match(/\[.\]/g) and then composes your arrays by adding two by two.
var matches = "Match[0][a][5][b][0][d][2]".match(/\[(.)\]/g);
var result = [];
for (var i = 0; i < matches.length; i += 2) {
var brackets = '';
for(var j = 0; j< i; j++) {
brackets += matches[j];
}
result.push("Match" + brackets);
}
result.shift();
Wow its fun :) ... trying api and see how everyone is solving it. This is what i tried see if this is helpful.
str = "STR[1][3][4d][re]"
var re=/\[\w+\]/g;
var mat = str.match(re);
var ar = [];
for(i=2; i<= mat.length; i=i+2){
ar[ar.length] = "STR" + mat.slice(0,i).join("")
}
console.dir(ar)
Related
I'm beginner in JS. I've tried to understand Caesar Cipher ROT13, but it was too complicated for me. So I've tried to write my own code. Here it is below:
function encrip() {
var alphabet = ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"];
var str = "Ni Hao";
var string = str.toUpperCase();
for (var i = 0; i < string.length; i++) {
for (var k = 0; k < alphabet.length; k++) {
if(string.charAt(i) == alphabet[k]) {
/* console.log(string.charAt(i) + ' ' + alphabet.indexOf(alphabet[k])); */
}
}
}
}
encrip();
But I am stuck. How to do:
1. Get value from var str and then access to var alphabet , after change each letter from var str value to next 3 from alphabet (var str each element's current position would be changed) For example: Input: Ni Hao ==> output: QL KDR
2. Create universal code, I mean, not only for changing position by 3, but when I give value '5', each element would be changed by next 5 positions from alphabet. So output can be changed when I change its' value
I hope I explained everything clearly. Thanks everyone in advance for help!!
you can use the following function to encrypt english words, the 1st parameter is the string to encrypt and the 2nd for shifting
function encryp(str,pos){
var alpha="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
var strUC=str.toUpperCase();
var enc="";
for(var i=0;i<strUC.length;i++){
if(strUC.charAt(i)!=" "){
enc+=alpha.charAt((alpha.indexOf(strUC.charAt(i))+pos)%26)
}
else{
enc+=" "
}
// in your case pos=3
}
return enc;
}
console.log(encryp("NiHao",3));
You don't need two for loops to do this. Iterate over the input string and find the index of each character in the alphabet array, if found add the shift to it to get the encrypted character.
To handle overflow use the modulus operator to cycle through the array.
Also I assume that you are not going use any special symbols to do the encryption.
function encrip(string, shift) {
var alphabet = ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"];
string = string.toUpperCase();
let arr = [];
for (var i = 0; i < string.length; i++) {
let char = alphabet.indexOf(string[i]) !== -1 ? alphabet[(alphabet.indexOf(string[i]) %26) + shift] : " ";
arr.push(char);
}
let encryp = arr.join("");
console.log(encryp);
return encryp;
}
encrip("Ni Hao", 3);
First of all, instead of your inner for loop scanning the whole alphabet array, you can use the built-in function indexOf:
alphabet.indexOf('K') // returns 10
Secondly, you'll want to build up your enciphered string in a separate variable. For each letter, get the index of that letter in the alphabet, add your cipher offset parameter to that index and add the resulting letter from the alphabet to your new string. An important step is that when you add to the index of the letter, you want to make sure the resulting index is within range for the alphabet array. You can do that using the % (modulo) operator, which will wrap high values back round to the start of the array. In full:
function encipher(input, offset) {
var alphabet = ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"];
var str = input.toUpperCase();
var result = '';
for (var i = 0; i < str.length; i++) {
letterIndex = alphabet.indexOf(str.charAt(i));
if (letterIndex === -1) {
result += str[i]; // if the letter isn't found in the alphabet, add it to the result unchanged
continue;
}
cipheredIndex = (letterIndex + offset) % alphabet.length; // wrap index to length of alphabet
result += alphabet[cipheredIndex];
}
console.log(result);
}
encipher('Ni Hao', 5); // output: 'SN MFT'
I have an array that returns some numbers like 222.000,333.000,444.000,555.000. Ideally I want to format so it places a breakline "\n" after every other number. i.e. Would be like
222.000,333.000
444.000,555.000
Can it be done by modifying the lines below?
n107 = parseFloat(output1),
n108 = parseFloat(output2),
n109 = parseFloat(output3),
n110 = parseFloat(output4),
list = [];
// add values to array if they're not NaN or > 0
if (n1) {
list.push(n1);
}
if (n2) {
list.push(n2);
}
if (n3) {
list.push(n3);
}
if (n4) {
list.push(n4);
}
if (n5) {
list.push(n5);
}
if (n6) {
list.push(n6);
}
// combine values into a string separated with commas
document.getElementById('inputTextToSave').innerHTML = list.join(",");
This is not a optimal solution.but it works
n107 = parseFloat("222.00"),
n108 = parseFloat("333.00"),
n109 = parseFloat("444.000"),
n110 = parseFloat("55.00"),
list = [n107,n108,n109,n110];
// combine values into a string separated with commas
//document.getElementById('inputTextToSave').innerHTML = list.join("</br>");
var j =1;
var htmlString = '';
for(var i =0; i< list.length; i++){
if(j<2){
htmlString += list[i]+",";
j++;
}else{
htmlString += list[i]+"</br>";
j=1;
}
}
document.getElementById('inputTextToSave').innerHTML = htmlString;
<div id="inputTextToSave"></div>
You need to create your own string in a loop instead of using join().
There are lots of ways to create the loop...the key is to check the index within the loop to determine which separator to use
var list = [222.000,333.000,444.000,555.000];
var res = list.reduce((newStr, currVal, index) =>
newStr += (index % 2 ===1 ? ',' :'\n') + currVal );
document.getElementById('inputTextToSave').innerHTML = res;
<pre id="inputTextToSave"></pre>
It can be done by using Array.reduce method.
const list = ['222.000', '333.000', '444.000', '555.000']
const result = list.reduce((memo, item, index) => {
const comma = (index+1)%2 === 0 ? ',' : ''
const lineBreak = (index+1)%2 === 0 ? '<br />' : ''
memo += comma + item + lineBreak
return memo
}, '')
document.getElementById('inputTextToSave').innerHTML = result;
<div id="inputTextToSave"></div>
you can try this function
function addBrakes(array){
let cutPoint = 3 // set where you want to cut
for(i=1; i<=array.length; i++){
if(i%cutPoint == 0){
array.splice(i, 0, "<br>")
}
}
}
Another option:
document.getElementById('inputTextToSave').innerHTML =
list.join(',').replace(/([^,]+,[^,]+),/g, '$1<br>')
I am working an anagram generator and am trying to break off each new item in the array into a new line. The way this works is it slices each array item and loops through each character.
The output needs to be:
cat, cta, act, atc, tca, tac,
bat, bta, abt, atb, tba, tab,
rat, rta, art, atr, tra, tar,
But it is:
cat, cta, act, atc, tca, tac, bat, bta, abt, atb, tba, tab, rat, rta, art, atr, tra, tar, splat, splta, spalt, spatl,...
So far the code I have is this:
HTML:
<div id="anagrams"></div>
JS:
var arr = ['cat', 'bat', 'rat', 'splat'];
var allAnagrams = function(arr) {
var anagrams = {};
arr.forEach(function(str) {
var recurse = function(ana, str) {
if (str === '')
anagrams[ana] = 1;
for (var i = 0; i < str.length; i++)
recurse(ana + str[i], str.slice(0, i) + str.slice(i + 1));
};
recurse(' ', str);
});
return Object.keys(anagrams);
}
document.getElementById("anagrams").innerHTML = (allAnagrams(arr));
To accomplish a new line per array item I basically want to check if the amount of the characters exceeds the amount of characters in the string/array item and if it does, insert a break into the HTML. I tried doing that by:
var arr = ['cat', 'bat', 'rat', 'splat'];
var allAnagrams = function(arr) {
var anagrams = {};
arr.forEach(function(str) {
var recurse = function(ana, str) {
if (str === '')
anagrams[ana] = 1;
for (var i = 0; i < str.length; i++)
recurse(ana + str[i], str.slice(0, i) + str.slice(i + 1));
// check if string length is greater than the count and
// if it is, insert a break between the string
if (i > str.length) {
recurse(' <br>', str);
}
};
recurse(' ', str);
});
return Object.keys(anagrams);
}
document.getElementById("anagrams").innerHTML = (allAnagrams(arr));
However it still prints across a single line. Am I approaching this the correct way? I also tried using ana in place of i but I think I need to use i since that's the actual count - is that correct?
A jsfiddle can be seen here: https://jsfiddle.net/4eqhd1m4/1/
I would slightly restructure the anagram creation.
Anagrams is now a string.
Recurse no longer takes care of adding break lines. Considering you want a break per element, it's cleaner to add it in the Array.forEach
jsfiddle
Edit
Adding a second jsfiddle to demonstrate the same behavior, except instead of using strings directly it returns an array (which gets split and rejoined using breaklines). It may be preferable to have the anagrams returned as an array.
jsfiddle
Is this is what you need ? All anagrams in different lines
var arr = ['cat', 'bat', 'rat', 'splat'];
var allAnagrams = function(arr) {
var anagrams = {};
arr.forEach(function(str) {
var recurse = function(ana, str) {
if (str === '')
anagrams[ana] = 1;
for (var i = 0; i < str.length; i++)
recurse(ana + str[i], str.slice(0, i) + str.slice(i + 1));
// check if string length is greater than the count and
// if it is, insert a break between the string
if (i > str.length) {
recurse(' <br \/>', str);
}
};
recurse(' <br \/>', str);
});
return Object.keys(anagrams);
}
document.getElementById("anagrams").innerHTML = (allAnagrams(arr));
<div id="anagrams"></div>
I am trying to use Javascript to split some data out of a url The url looks along the lines of....
var1=green&var2=yellow&newUrl=[url.php?id=2]
I am managing to split the url by the '&' signs to give me one array of three items. I am then trying to split this array by the first '=' sign to give me a list of fields and variables. Its working fine until it hits the second = sign within the newUrl field. Any ideas of how I can split this string at the first '=' sign.
my code so far is...
var href = $(this).attr("href");
var vars = href.split("&");
for(i=0; i < vars.length; ++i){
var str = vars[i].split("=");
alert(str[0] +':' +str[1]);
}
}
my results are
var1:green var2:yellow var3:[url.php?id
Any ideas?
**Edit to show my final code based on Wand Maker's solution **
var vars = href.split("&");
for(i=0; i < vars.length; ++i){
index = vars[i].indexOf("=")
var str = [ vars[i].substring(0, index), vars[i].substring(index)]
alert(str[0] +':' +str[1].substring(1);
}
Try something like below for splitting around =
index = vars[i].indexOf("=")
var str = [ vars[i].substring(0, index), vars[i].substring(index)]
You could use join() for the third element in the array as below:
var lst = href.split("&");
var var1 = href[0].split("=")[1];
var var2 = href[1].split("=")[1];
var var3 = href[2].split("=").slice(1,2).join("");
function splitFirstInstance(str,item){
var res = [];
var found = true;
res.push("");
for (var i = 0; i < str.length;i++){
if (str[i] === item && found === true){
res.push("");
found = false;
} else {
res[res.length-1] += str[i];
}
}
return res;
}
splitstr("I Want to Split First a","a"); // ["I W","nt to Split First a"]
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]).