I have a string like this:
(apple,apple,orange,banana,strawberry,strawberry,strawberry). I want to count the number of occurrences for each of the characters, e.g. banana (1) apple(2) and strawberry(3). how can I do this?
The closest i could find was something like, which i dont know how to adapt for my needs:
function countOcurrences(str, value){
var regExp = new RegExp(value, "gi");
return str.match(regExp) ? str.match(regExp).length : 0;
}
Here is the easiest way to achieve that by using arrays.. without any expressions or stuff. Code is fairly simple and self explanatory along with comments:
var str = "apple,apple,orange,banana,strawberry,strawberry,strawberry";
var arr = str.split(','); //getting the array of all fruits
var counts = {}; //this array will contain count of each element at it's specific position, counts['apples']
arr.forEach(function(x) { counts[x] = (counts[x] || 0)+1; }); //checking and addition logic.. e.g. counts['apples']+1
alert("Apples: " + counts['apple']);
alert("Oranges: " + counts['orange']);
alert("Banana: " + counts['banana']);
alert("Strawberry: " + counts['strawberry']);
See the DEMO here
You can try
var wordCounts = str.split(",").reduce(function(result, word){
result[word] = (result[word] || 0) + 1;
return result;
}, {});
wordCounts will be a hash {"apple":2, "orange":1, ...}
You can print it as the format you like.
See the DEMO http://repl.it/YCO/10
You can use split also:
function getCount(str,d) {
return str.split(d).length - 1;
}
getCount("fat math cat", "at"); // return 3
Related
how would you go about outputting the found output, including the rest of the string its apart of? The array is just full of strings. Thanks
var searchingfor = document.getElementById('searchfield').value;
var searchingforinlowerCase = searchingfor.toLowerCase();
var searchDiv = document.getElementById('searchDiv');
var convertarraytoString = appointmentArr.toString();
var arraytolowerCase = convertarraytoString.toLowerCase();
var splitarrayString = arraytolowerCase.split(',')
if(search(searchingforinlowerCase, splitarrayString) == true) {
alert( searchingforinlowerCase + ' was found at index' + searchLocation(searchingforinlowerCase,splitarrayString) + ' Amount of times found = ' +searchCount(searchingforinlowerCase,splitarrayString));
function search(target, arrayToSearchIn) {
var i;
for (i=0; i<arrayToSearchIn.length; i++)
{ if (arrayToSearchIn[i] == target && target !=="")
return true;
}
Try this
if(search(searchingforinlowerCase, appointmentArr) == true) {
alert( searchingforinlowerCase + ' was found at index' + searchLocation(searchingforinlowerCase,splitarrayString) + ' Amount of times found = ' +searchCount(searchingforinlowerCase,splitarrayString));
function search(target, arrayToSearchIn) {
var i;
for (i=0; i<arrayToSearchIn.length; i++)
{ if (arrayToSearchIn[i].indexOf(target >= 0))
return true;
}
return false;
}
This code will help you find that a match is present. You can update code to display full text where match was found. Original posted code was comparing entire string rather than partial match.
You can do like this
var test = 'Hello World';
if (test.indexOf('Wor') >= 0)
{
/* found substring Wor */
}
In your posted code you are converting Array to string and then again converting it back to Array using split(). That is unnecessary. search can be invoked as
search(searchingforinlowerCase, appointmentArr);
Try utilizing Array.prototype.filter() , String.prototype.indexOf()
// input string
var str = "america";
// array of strings
var arr = ["First Name: John, Location:'america'", "First Name: Jane, Location:'antarctica'"];
// filter array of strings
var res = arr.filter(function(value) {
// if `str` found in `value` , return string from `arr`
return value.toLowerCase().indexOf(str.toLowerCase()) !== -1
});
// do stuff with returned single , or strings from `arr`
console.log(res, res[0])
The following will look for a word in an array of strings and return all the strings that match the word. Is this something you are looking for?
var a = ["one word", "two sentence", "three paragraph", "four page", "five chapter", "six section", "seven book", "one, two word", "two,two sentence", "three, two paragraph", "four, two page", "five, two chapter",];
function search(needle, haystack){
var results = [];
haystack.forEach(function(str){
if(str.indexOf(needle) > -1){
results.push(str);
}
});
return results.length ? results : '';
};
var b = search("word", a);
console.log(b);
Here's the fiddle to try.
Say for example I have
var input = "C\\\\Program Files\\\\Need for Speed";
var output = do_it(input, ':');
Now, I would like output to have the value below :
C:\\\\Program Files\\\\Need for Speed
I need to add a character to the given string just after the first character. How can I achieve that using javascript or jquery ?
Thanks in advance
It's probably not the most efficient way, but I would do something like:
(note: this is just pseudocode)
var output = input[0] + ":" + input.substr(1, input.length);
you can use this like
String.prototype.addAt = function (index, character) {
return this.substr(0, index - 1) + character + this.substr(index-1 + character.length-1);
}
var input = "C\\Program Files\\Need for Speed";
var result = input.addAt(2, ':');
Heres one way of doing it:
Fiddle: http://jsfiddle.net/FjfB9/
var input = "C\\Program Files\\Need for Speed"
var do_it = function(str, char) {
var str = str.split(''),
temp = str.shift()
str.unshift(temp, char)
return str.join('')
}
console.log(do_it(input, ":"))
Here's a thing i've been trying to resolve...
We've got some data from an ajax call and the result data is between other stuff a huge string with key:value data. For example:
"2R=OK|2M=2 row(s) found|V1=1,2|"
Is it posible for js to do something like:
var value = someFunction(str, param);
so if i search for "V1" parameter it will return "1,2"
I got this running on Sql server no sweat, but i'm struggling with js to parse the string.
So far i'm able to do this by a VERY rudimentary for loop like this:
var str = "2R=OK|2M=2 row(s) found|V1=1,2|";
var param = "V1";
var arr = str.split("|");
var i = 0;
var value = "";
for(i = 0; i<arr.length; ++i){
if( arr[i].indexOf(param)>-1 ){
value = arr[i].split("=")[1];
}
}
console.log(value);
if i put that into a function it works, but i wonder if there's a more efficient way to do it, maybe some regex? but i suck at it. Hopefully somebody may shine a light on this for me?
Thanks!
This seems to work for your specific use-case:
function getValueByKey(haystack, needle) {
if (!haystack || !needle) {
return false;
}
else {
var re = new RegExp(needle + '=(.+)');
return haystack.match(re)[1];
}
}
var str = "2R=OK|2M=2 row(s) found|V1=1,2|",
test = getValueByKey(str, 'V1');
console.log(test);
JS Fiddle demo.
And, to include the separator in your search (in order to prevent somethingElseV1 matching for V1):
function getValueByKey(haystack, needle, separator) {
if (!haystack || !needle) {
return false;
}
else {
var re = new RegExp('\\' + separator + needle + '=(.+)\\' + separator);
return haystack.match(re)[1];
}
}
var str = "2R=OK|2M=2 row(s) found|V1=1,2|",
test = getValueByKey(str, 'V1', '|');
console.log(test);
JS Fiddle demo.
Note that this approach does require the use of the new RegExp() constructor (rather than creating a regex-literal using /.../) in order to pass variables into the regular expression.
Similarly, because we're using a string to create the regular expression within the constructor, we need to double-escape characters that require escaping (escaping first within the string and then escaping within in the created RegExp).
References:
RegExp.
String.match().
This should work for you and it's delimiters are configurable (if you wish to parse a similar string with different delimiters, you can just pass in the delimiters as arguments):
var parseKeyValue = (function(){
return function(str, search, keyDelim, valueDelim){
keyDelim = quote(keyDelim || '|');
valueDelim = quote(valueDelim || '=');
var regexp = new RegExp('(?:^|' + keyDelim + ')' + quote(search) + valueDelim + '(.*?)(?:' + keyDelim + '|$)');
var result = regexp.exec(str);
if(result && result.length > 1)
return result[1];
};
function quote(str){
return (str+'').replace(/([.?*+^$[\]\\(){}|-])/g, "\\$1");
}
})();
Quote function borrowed form this answer
Usage examples:
var str = "2R=OK|2M=2 row(s) found|V1=1,2|";
var param = "V1";
parseKeyValue(str, param); // "1,2"
var str = "2R=OK&2M=2 row(s) found&V1=1,2";
var param = "2R";
parseKeyValue(str, param, '&'); // "OK"
var str =
"2R=>OK\n\
2M->2 row(s) found\n\
V1->1,2";
var param = "2M";
parseKeyValue(str, param, '\n', '->'); // "2 row(s) found"
Here is another approach:
HTML:
<div id="2R"></div>
<div id="2M"></div>
<div id="V1"></div>
Javascript:
function createDictionary(input) {
var splittedInput = input.split(/[=|]/),
kvpCount = Math.floor(splittedInput.length / 2),
i, key, value,
dictionary = {};
for (i = 0; i < kvpCount; i += 1) {
key = splittedInput[i * 2];
value = splittedInput[i * 2 + 1];
dictionary[key] = value;
}
return dictionary;
}
var input = "2R=OK|2M=2 row(s) found|V1=1,2|",
dictionary = createDictionary(input),
div2R = document.getElementById("2R"),
div2M = document.getElementById("2M"),
divV1 = document.getElementById("V1");
div2R.innerHTML = dictionary["2R"];
div2M.innerHTML = dictionary["2M"];
divV1.innerHTML = dictionary["V1"];
Result:
OK
2 row(s) found
1,2
Is there a possibility to wrap each character in Javascript and prepend zero's if its less then X digits?
What i get/have:
var votes = 2;
//or
var votes = 123;
//or
var votes = 4321;
what it should to look like:
<span>0</span><span>0</span><span>0</span><span>2</span>
//or
<span>0</span><span>1</span><span>2</span><span>3</span>
//or
<span>4</span><span>3</span><span>2</span><span>1</span>
so the result should be a number with four digits.
here's a tricky version:
var votes = 123;
("0000" + votes).slice(-4); /* 0123 */
thus, to wrap each digit in a <span> you could fetch each digit with $.map and wrap it into its own element, like in this example fiddle: http://jsfiddle.net/cZAWj/
var votes = 973;
$.map(("0000" + votes).slice(-4), function(digit) {
$('<span/>', { text : digit }).appendTo($('body'));
});
Firstly, make it look like a string and pad it...
function pad(number, length) {
var str = '' + number;
while (str.length < length) {
str = '0' + str;
}
return str;
}
Then you can iterate over it and add a span around each number. Then write the markup out as the .html of the parent element.
Well one way to do it would be to convert the number to a string and pre-append 0 until we reach the desired length.
So if you want X digits:
var strNb = "" + nb;
while (strNb.length < X){
strNb = "0" + strNb
}
function formatNumber(d, x) {
var l = String(d).length;
return (l<x?(Array(x-l).join('0') + d):String(d)).replace(/\d/g,"<span>$&</span>");
}
I want to remove all occurrences of substring = . in a string except the last one.
E.G:
1.2.3.4
should become:
123.4
You can use regex with positive look ahead,
"1.2.3.4".replace(/[.](?=.*[.])/g, "");
2-liner:
function removeAllButLast(string, token) {
/* Requires STRING not contain TOKEN */
var parts = string.split(token);
return parts.slice(0,-1).join('') + token + parts.slice(-1)
}
Alternative version without the requirement on the string argument:
function removeAllButLast(string, token) {
var parts = string.split(token);
if (parts[1]===undefined)
return string;
else
return parts.slice(0,-1).join('') + token + parts.slice(-1)
}
Demo:
> removeAllButLast('a.b.c.d', '.')
"abc.d"
The following one-liner is a regular expression that takes advantage of the fact that the * character is greedy, and that replace will leave the string alone if no match is found. It works by matching [longest string including dots][dot] and leaving [rest of string], and if a match is found it strips all '.'s from it:
'a.b.c.d'.replace(/(.*)\./, x => x.replace(/\./g,'')+'.')
(If your string contains newlines, you will have to use [.\n] rather than naked .s)
You can do something like this:
var str = '1.2.3.4';
var last = str.lastIndexOf('.');
var butLast = str.substring(0, last).replace(/\./g, '');
var res = butLast + str.substring(last);
Live example:
http://jsfiddle.net/qwjaW/
You could take a positive lookahead (for keeping the last dot, if any) and replace the first coming dots.
var string = '1.2.3.4';
console.log(string.replace(/\.(?=.*\.)/g, ''));
A replaceAllButLast function is more useful than a removeAllButLast function. When you want to remove just replace with an empty string:
function replaceAllButLast(str, pOld, pNew) {
var parts = str.split(pOld)
if (parts.length === 1) return str
return parts.slice(0, -1).join(pNew) + pOld + parts.slice(-1)
}
var test = 'hello there hello there hello there'
test = replaceAllButLast(test, ' there', '')
console.log(test) // hello hello hello there
Found a much better way of doing this. Here is replaceAllButLast and appendAllButLast as they should be done. The latter does a replace whilst preserving the original match. To remove, just replace with an empty string.
var str = "hello there hello there hello there"
function replaceAllButLast(str, regex, replace) {
var reg = new RegExp(regex, 'g')
return str.replace(reg, function(match, offset, str) {
var follow = str.slice(offset);
var isLast = follow.match(reg).length == 1;
return (isLast) ? match : replace
})
}
function appendAllButLast(str, regex, append) {
var reg = new RegExp(regex, 'g')
return str.replace(reg, function(match, offset, str) {
var follow = str.slice(offset);
var isLast = follow.match(reg).length == 1;
return (isLast) ? match : match + append
})
}
var replaced = replaceAllButLast(str, / there/, ' world')
console.log(replaced)
var appended = appendAllButLast(str, / there/, ' fred')
console.log(appended)
Thanks to #leaf for these masterpieces which he gave here.
You could reverse the string, remove all occurrences of substring except the first, and reverse it again to get what you want.
function formatString() {
var arr = ('1.2.3.4').split('.');
var arrLen = arr.length-1;
var outputString = '.' + arr[arrLen];
for (var i=arr.length-2; i >= 0; i--) {
outputString = arr[i]+outputString;
}
alert(outputString);
}
See it in action here: http://jsbin.com/izebay
var s='1.2.3.4';
s=s.split('.');
s.splice(s.length-1,0,'.');
s.join('');
123.4