Format number with spaces in text using regex

fomatNumberInString.js

let str = 'This string contains two numbers. One is 50000 and the second one is 10000.';

// Edit (\s|\.) if the character after the number is not whitespace or dot
// Edit '$& ' if you want to insert different character from whitespace, for example to format number using ',' replace whitespace with '$&,'
console.log(str.replace(/\d(?=(\d{3})+(\s|\.))/g, '$& '));

// or

console.log(str.replace(/\B(?=(\d{3})+(?!\d))/g, " "));

// Output: This string contains two numbers. One is 50 000 and the second one is 10 000.


// suports also only number
function formatNumber(exp) { return exp.toString().replace(/\B(?=(\d{3})+(?!\d))/g, " "); }