[javascript] 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"

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(" ") )

I 'm using this :

function getFirstWord(str) {
        let spaceIndex = str.indexOf(' ');
        return spaceIndex === -1 ? str : str.substr(0, spaceIndex);
    };

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);
}

In modern JS, this is simplified, and you can write something like this:

const firstWords = str =>_x000D_
  str .split (/\|/) .map (s => s .split (/\s+/) [0])_x000D_
_x000D_
const str = "Hello m|sss sss|mmm ss"_x000D_
_x000D_
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.

Use regular expression

var totalWords = "foo love bar very much.";_x000D_
_x000D_
var firstWord = totalWords.replace(/ .*/,'');_x000D_
_x000D_
$('body').append(firstWord);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

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'));

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)
}

To get first word of string you can do this:

let myStr = "Hello World"
let firstWord = myStr.split(" ")[0]

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]);
 }

One of the simplest ways to do this is like this

var totalWords = "my name is rahul.";_x000D_
var firstWord = totalWords.replace(/ .*/, '');_x000D_
alert(firstWord);_x000D_
console.log(firstWord);

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.*/,'')}_x000D_
console.log(`linebreak_x000D_
example 1`.firstWord()); // -> linebreak_x000D_
console.log('space example 2'.firstWord()); // -> singleline_x000D_
console.log('tab example 3'.firstWord()); // -> tab