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);
}

I 'm using this :

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

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.

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"