Use match() method with RegEx and join() method to get first letter of each word in JavaScript. Where join method to join the array into a string.
Get the first letter of each word in JavaScript
Simple example code.
<!DOCTYPE html>
<html>
<body>
<script>
var str = "Java Script Object Notation";
var matches = str.match(/\b(\w)/g);
var acronym = matches.join('');
console.log(acronym)
</script>
</body>
</html>
Output:

Another way
let str = "Java Script Object Notation";
let acronym = str.split(/\s/).reduce((response,word)=> response+=word.slice(0,1),'')
console.log(acronym);
OR
function getFirstLetters(str) {
const firstLetters = str
.split(' ')
.map(word => word[0])
.join('');
return firstLetters;
}
// 👇️ ABC
console.log(getFirstLetters('Alice, Bob, Charlie'));
// 👇️ ONE
console.log(getFirstLetters('Oscar Noah Emily.'));
Do comment if you have any doubts or suggestions on this JS code.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version

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