Get first letter of each word in a string, in JavaScript

Question

How would you go around to collect the first letter of each word in a string, as in to receive an abbreviation?

Input: "Java Script Object

Answer 1

This is made very simple with ES6

string.split(' ').map(i => i.charAt(0))               //Inherit case of each letter
string.split(' ').map(i => i.charAt(0)).toUpperCase() //Uppercase each letter
string.split(' ').map(i => i.charAt(0)).toLowerCase() //lowercase each letter

This ONLY works with spaces or whatever is defined in the .split(' ') method

ie, .split(', ') .split('; '), etc..

Answer 2

@BotNet flaw: i think i solved it after excruciating 3 days of regular expressions tutorials:

==> I'm a an animal

(used to catch m of I'm) because of the word boundary, it seems to work for me that way.

/(\s|^)([a-z])/gi

Answer 3

This is similar to others, but (IMHO) a tad easier to read:

const getAcronym = title =>
  title.split(' ')
    .map(word => word[0])
    .join('');

Answer 4

Try -

var text = '';
var arr = "Java Script Object Notation".split(' ');
for(i=0;i<arr.length;i++) {
    text += arr[i].substr(0,1)
}    
alert(text);

Demo - http://jsfiddle.net/r2maQ/

Answer 5

How about this:

var str = "", abbr = "";
str = "Java Script Object Notation";
str = str.split(' ');
for (i = 0; i < str.length; i++) {
    abbr += str[i].substr(0,1);
}
alert(abbr);

Working Example.

Answer 6

Alternative 1:

you can also use this regex to return an array of the first letter of every word

/(?<=(\s|^))[a-z]/gi

(?<=(\s|^)) is called positive lookbehind which make sure the element in our search pattern is preceded by (\s|^).

---

so, for your case:

// in case the input is lowercase & there's a word with apostrophe

const toAbbr = (str) => {
  return str.match(/(?<=(\s|^))[a-z]/gi)
            .join('')
            .toUpperCase();
};

toAbbr("java script object notation"); //result JSON

---

(by the way, there are also negative lookbehind, positive lookahead, negative lookahead, if you want to learn more)

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Alternative 2:

match all the words and use replace() method to replace them with the first letter of each word and ignore the space (the method will not mutate your original string)

// in case the input is lowercase & there's a word with apostrophe    

const toAbbr = (str) => {
  return str.replace(/(\S+)(\s*)/gi, (match, p1, p2) => p1[0].toUpperCase());
};

toAbbr("java script object notation"); //result JSON

// word = not space = \S+ = p1 (p1 is the first pattern)
// space = \s* = p2 (p2 is the second pattern)