Develop Reference

Separate characters and numbers from a string

I have a string variable that contain character and numbers like this
var sampleString = "aaa1211"
Note that variable always start with a character/s and end with number/s. Character and number size is not fixed. It could be something like followings
var sampleString = "aaaaa12111"
var sampleString = "aaa12111"
I need to separate the characters and numbers and assign them into separate variables.
How could I do that ?
I try to use split and substring but for this scenario I couldn't apply those. I know this is a basic question but i'm search over the internet and I was unable to find an answer.
Thank you

Please use
[A-Za-z] - all letters (uppercase and lowercase)
[0-9] - all numbers
function myFunction() {
var str = "aaaaAZE12121212";
var patt1 = /[0-9]/g;
var patt2 = /[a-zA-Z]/g;
var letters = str.match(patt2);
var digits = str.match(patt1);
document.getElementById("alphabets").innerHTML = letters;
document.getElementById("numbers").innerHTML = digits;
}
Codepen-http://codepen.io/nagasai/pen/pbbGOB

A shorter solution if the string always starts with letters and ends with numbers as you say:
var str = 'aaaaa12111';
var chars = str.slice(0, str.search(/\d/));
var numbs = str.replace(chars, '');
console.log(chars, numbs);

You can use it in a single regex,
var st = 'red123';
var regex = new RegExp('([0-9]+)|([a-zA-Z]+)','g');
var splittedArray = st.match(regex);
var num= splittedArray[0];
var text = splittedArray[1];
this will give you both the text and number.

Using Match
const str = "ASDF1234";
const [word, digits] = str.match(/\D+|\d+/g);
console.log(word); // "ASDF"
console.log(digits); // "1234"
The above will work even if your string starts with digits.
Using Split
with Positive lookbehind (?<=) and Positive lookahead (?=):
const str = "ASDF1234";
const [word, digits] = str.split(/(?<=\D)(?=\d)/);
console.log(word); // "ASDF"
console.log(digits); // "1234"
where \D stands for not a digit and \d for digit.

Use isNaN() to differentiate
var sampleString = "aaa1211"
var newnum =""
var newstr =""
for(var i=0;i<sampleString.length;i++){
if(isNaN(sampleString[i])){
newstr = newstr+sampleString[i]
}else{
newnum= newstr+sampleString[i]
}
}
console.log(newnum) //1121
console.log(newstr) //aaa

If you're like me, you were looking to separate alphabets and numbers, no matter what their position is, Try this:
var separateTextAndNum = (x) => {
var textArray = x.split('')
var text = []
var num = []
textArray.forEach(t=>{
if (t>-1) {
num.push(t)
} else {
text.push(t)
}
})
return [text, num]
}
For ex - if you try this:
separateTextAndNum('abcd1234ava') // result [["a","b","c","d","a","v","a"],["1","2","3","4"]]

This isn't beautiful but it works.
function splitLettersAndNumbers(string) {
var numbers = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];
var numbers, letters, splitIndex;
for (var i = 0; i < string.length; i++) {
if (numbers.indexOf(string[i]) > -1) {
letters = string.substring(0, i);
numbers = string.substring(i);
return [letters, numbers];
}
}
// in the chance that you don't find any numbers just return the initial string or array of the string of letters
return [string];
}
Essentially just looping through the string until you find a number and you split it at that index. Returning a tuple with your letters and numbers. So when you run it you can do something like this:
var results = splitLettersAndNumbers(string);
var letters = results[0];
var numbers = results[1];

A functional approach...
var sampleString = "aaaaa12111";
var seperate = sampleString.split('').reduce(function(start , item){
Number(item) ? start[0] += item : start[1] += item;
return start
},['',''])
console.log(seperate) //["12111", "aaaaa"]

You can loop through the string length, check it & add to the variable.
It is not clear if you want to assign each of the character to a variable or all alphabets to one variable & integers to another.
var sampleString = "aaa12111"
var _num = "";
var _alp = "";
for (var i = 0; i < sampleString.length; i++) {
if (isNaN(sampleString[i])) {
_num += sampleString[i];
} else {
_alp += sampleString[i];
}
}
console.log(_num, _alp)

How to get substring value from main string?

I have string similar to this one.
HTML
var str = "samplestring=:customerid and samplestring1=:dept";
JS
var parts = str.split(':');
var answer = parts;
I want to trim substrings which starts with colon: symbol from the main string
But it is returing the value like this
samplestring=,customerid and samplestring1=,dept
But I want it something like this.
customerid,dept
I am getting main string dynamically it may have colon more then 2.
I have created a fiddle also link

var str = "samplestring=:customerid and samplestring1=:dept";
alert(str.match(/:(\w+)/g).map(function(s){return s.substr(1)}).join(","))

you can try regex:
var matches = str.match(/=:(\w+)/g);
var answer = [];
if(matches){
matches.forEach(function(s){
answer.push(s.substr(2));
});
}

Here's a one-liner:
$.map(str.match(/:(\w+)/g), function(e, v) { return e.substr(1); }).join(",")

Try
var str = "samplestring=:customerid and samplestring1=:dept";
var parts = str.split(':');
var dept = parts[2];
var cus_id = parts[1].split(' and ')[0];
alert(cus_id + ", " + dept );
Using this you will get o/p like :customerid,dept

this will give you what you need...
var str = "samplestring=:customerid and samplestring1=:dept";
var parts = str.split(' and ');
var answer = [];
for (var i = 0; i < parts.length; i++) {
answer.push(parts[i].substring(parts[i].indexOf(':')+1));
}
alert(answer);

var str = "samplestring=:customerid and samplestring1=:dept";
alert(str.replace(/[^:]*:(\w+)/g, ",$1").substr(1))

You can try it like this
var str = "samplestring=:customerid and samplestring1=:dept and samplestring11=:dept";
var results = [];
var parts = str.split(' and ');
$.each(parts, function( key, value ) {
results.push(value.split(':')[1]);
});
Now the results array contains the three values customerid, dept, and dept

Here \S where S is capital is to get not space characters so it will get the word till first space match it, so it will match the word after : till the first space and we use /g to not only match the fisrt word and continue search in the string for other matches:
str.match(/:(\S*)/g).map(function(s){return s.substr(1)}).join(",")

JavaScript Split, Split string by last DOT "."

JavaScript Split,
str = '123.2345.34' ,
expected output 123.2345 and 34
Str = 123,23.34.23
expected output 123,23.34 and 23
Goal : JS function to Split a string based on dot(from last) in O(n).
There may be n number of ,.(commas or dots) in string.

In order to split a string matching only the last character like described you need to use regex "lookahead".
This simple example works for your case:
var array = '123.2345.34'.split(/\.(?=[^\.]+$)/);
console.log(array);
Example with destructuring assignment (Ecmascript 2015)
const input = 'jquery.somePlugin.v1.6.3.js';
const [pluginName, fileExtension] = input.split(/\.(?=[^\.]+$)/);
console.log(pluginName, fileExtension);
However using either slice or substring with lastIndexOf also works, and albeit less elegant it's much faster:
var input = 'jquery.somePlugin.v1.6.3.js';
var period = input.lastIndexOf('.');
var pluginName = input.substring(0, period);
var fileExtension = input.substring(period + 1);
console.log(pluginName, fileExtension);

var str = "filename.to.split.pdf"
var arr = str.split("."); // Split the string using dot as separator
var lastVal = arr.pop(); // Get last element
var firstVal = arr.join("."); // Re-join the remaining substrings, using dot as separator
console.log(firstVal + " and " + lastVal); //Printing result

I will try something like bellow
var splitByLastDot = function(text) {
var index = text.lastIndexOf('.');
return [text.slice(0, index), text.slice(index + 1)]
}
console.log(splitByLastDot('123.2345.34'))
console.log(splitByLastDot('123,23.34.23'))

I came up with this:
var str = '123,23.34.23';
var result = str.replace(/\.([^.]+)$/, ':$1').split(':');
document.getElementById('output').innerHTML = JSON.stringify(result);
<div id="output"></div>

let returnFileIndex = str =>
str.split('.').pop();

Try this:
var str = '123.2345.34',
arr = str.split('.'),
output = arr.pop();
str = arr.join('.');

var test = 'filename.....png';
var lastStr = test.lastIndexOf(".");
var str = test.substring(lastStr + 1);
console.log(str);

I'm typically using this code and this works fine for me.
Jquery:
var afterDot = value.substr(value.lastIndexOf('_') + 1);
console.log(afterDot);
Javascript:
var myString = 'asd/f/df/xc/asd/test.jpg'
var parts = myString.split('/');
var answer = parts[parts.length - 1];
console.log(answer);
Note: Replace quoted string to your own need

My own version:
var mySplit;
var str1;
var str2;
$(function(){
mySplit = function(myString){
var lastPoint = myString.lastIndexOf(".");
str1 = myString.substring(0, lastPoint);
str2 = myString.substring(lastPoint + 1);
}
mySplit('123,23.34.23');
console.log(str1);
console.log(str2);
});
Working fiddle: https://jsfiddle.net/robertrozas/no01uya0/

Str = '123,23.34.23';
var a = Str.substring(0, Str.lastIndexOf(".")) //123,23.34
var b = Str.substring(Str.lastIndexOf(".")) //23

Try this solution.
Simple Spilt logic
<script type="text/javascript">
var str = "123,23.34.23";
var str_array = str.split(".");
for (var i=0;i<str_array.length;i++)
{
if (i == (str_array.length-1))
{
alert(str_array[i]);
}
}
</script>

The simplest way is mentioned below, you will get pdf as the output:
var str = "http://somedomain.com/dir/sd/test.pdf";
var ext = str.split('.')[str.split('.').length-1];
Output: pdf

Select 2 characters after a particular substring in javascript

We have a string ,
var str = "Name=XYZ;State=TX;Phone=9422323233";
Here in the above string we need to fetch only the State value i.e TX. That is 2 characters after the substring State=
Can anyone help me implement it in javascript.

.split() the string into array and then find the index of the array element having State string. Using that index get to that element and again .split() it and get the result. Try this way,
var str = "Name=XYZ;State=TX;Phone=9422323233";
var strArr = str.split(';');
var index = 0;
for(var i = 0; i < strArr.length; i++){
if(strArr[i].match("State")){
index = i;
}
}
console.log(strArr[index].split('=')[1]);
jsFiddle

I guess the easiest way out is by slicing and splitting
var str = "Name=XYZ;State=TX;Phone=9422323233";
var findme = str.split(';')[1];
var last2 = findme.slice(-2);
alert(last2);
Need more help? Let me know

indexOf returns the position of the string in the other string.
Using this index you can find the next two characters
javascript something like
var n = str.indexOf("State=");
then use slice method
like
var res = str.slice(n,n+2);
another method is :
use split function
var newstring=str.split("State=");
then
var result=newstring.substr(0, 2);

Check this:
var str1 = "Name=XYZ;State=TX;Phone=9422323233";
var n = str1.search("State");
n=n+6;
var res = str1.substr(n, 2);
The result is in the variable res, no matter where State is in the original string.

There are any number of ways to get what you're after:
var str = "Name=XYZ;State=TX;Phone=9422323233"
Using match:
var match = str.match(/State=.{2}/);
var state = match? match[0].substring(6) : '';
console.log(state);
Using replace:
var state = str.replace(/^.*State=/,'').substring(0,2);
console.log(state);
Using split:
console.log(str.split('State=')[1].substring(0,2));
There are many other ways, including constructing an object that has name/value pairs:
var obj = {};
var b = str.split(';');
var c;
for (var i=b.length; i; ) {
c = b[--i].split('=');
obj[c[0]] = c[1];
}
console.log(obj.State);
Take your pick.

Get first word of string

Okay, here is my code with details of what I have tried to do:
var str = "Hello m|sss sss|mmm ss";
//Now I separate them by "|"
var str1 = str.split("|");
//Now I want to get the first word of every split-ed sting parts:
for (var i = 0; i < codelines.length; i++) {
//What to do here to get the first word of every spilt
}
So what should I do there? :\
What I want to get is :
firstword[0] will give "Hello"
firstword[1] will give "sss"
firstword[2] will give "mmm"

Use regular expression
var totalWords = "foo love bar very much.";
var firstWord = totalWords.replace(/ .*/,'');
$('body').append(firstWord);
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

Split again by a whitespace:
var firstWords = [];
for (var i=0;i<codelines.length;i++)
{
var words = codelines[i].split(" ");
firstWords.push(words[0]);
}
Or use String.prototype.substr() (probably faster):
var firstWords = [];
for (var i=0;i<codelines.length;i++)
{
var codeLine = codelines[i];
var firstWord = codeLine.substr(0, codeLine.indexOf(" "));
  firstWords.push(firstWord);
}

To get first word of string you can do this:
let myStr = "Hello World"
let firstWord = myStr.split(" ")[0]
console.log(firstWord)
split(" ") will convert your string into an array of words (substrings resulted from the division of the string using space as divider) and then you can get the first word accessing the first array element with [0].
See more about the split method.

I 'm using this :
function getFirstWord(str) {
let spaceIndex = str.indexOf(' ');
return spaceIndex === -1 ? str : str.substring(0, spaceIndex);
};

How about using underscorejs
str = "There are so many places on earth that I want to go, i just dont have time. :("
firstWord = _.first( str.split(" ") )

An improvement upon previous answers (working on multi-line or tabbed strings):
String.prototype.firstWord = function(){return this.replace(/\s.*/,'')}
Or using search and substr:
String.prototype.firstWord = function(){let sp=this.search(/\s/);return sp<0?this:this.substr(0,sp)}
Or without regex:
String.prototype.firstWord = function(){
let sps=[this.indexOf(' '),this.indexOf('\u000A'),this.indexOf('\u0009')].
filter((e)=>e!==-1);
return sps.length? this.substr(0,Math.min(...sps)) : this;
}
Examples:
String.prototype.firstWord = function(){return this.replace(/\s.*/,'')}
console.log(`linebreak
example 1`.firstWord()); // -> linebreak
console.log('space example 2'.firstWord()); // -> singleline
console.log('tab example 3'.firstWord()); // -> tab

var str = "Hello m|sss sss|mmm ss"
//Now i separate them by "|"
var str1 = str.split('|');
//Now i want to get the first word of every split-ed sting parts:
for (var i=0;i<str1.length;i++)
{
//What to do here to get the first word :)
var firstWord = str1[i].split(' ')[0];
alert(firstWord);
}

This code should get you the first word,
var str = "Hello m|sss sss|mmm ss"
//Now i separate them by "|"
var str1 = str.split('|');
//Now i want to get the first word of every split-ed sting parts:
for (var i=0;i<str1.length;i++)
{
//What to do here to get the first word :(
var words = str1[i].split(" ");
console.log(words[0]);
}

In modern JS, this is simplified, and you can write something like this:
const firstWords = str =>
str .split (/\|/) .map (s => s .split (/\s+/) [0])
const str = "Hello m|sss sss|mmm ss"
console .log (firstWords (str))
We first split the string on the | and then split each string in the resulting array on any white space, keeping only the first one.

I'm surprised this method hasn't been mentioned: "Some string".split(' ').shift()
To answer the question directly:
let firstWords = []
let str = "Hello m|sss sss|mmm ss";
const codeLines = str.split("|");
for (var i = 0; i < codeLines.length; i++) {
const first = codeLines[i].split(' ').shift()
firstWords.push(first)
}

const getFirstWord = string => {
const firstWord = [];
for (let i = 0; i < string.length; i += 1) {
if (string[i] === ' ') break;
firstWord.push(string[i]);
}
return firstWord.join('');
};
console.log(getFirstWord('Hello World'));
or simplify it:
const getFirstWord = string => {
const words = string.split(' ');
return words[0];
};
console.log(getFirstWord('Hello World'));

This code should get you the first word,
const myName = 'Jahid Bhuiyan';
console.log(myName.slice(0, myName.indexOf(' ')));
Ans will be "Jahid"