Replace last index of , with and in jQuery /JavaScript

Question

i want to replace the last index of comma (,)in string with and.

eg . a,b,c with 'a,b and c'

eg q,w,e with q,w and e

Solution 1

DEMO

lastIndexOf finds the last index of the parameter string passed in it.

var x = 'a,b,c';
var pos = x.lastIndexOf(',');
x = x.substring(0,pos)+' and '+x.substring(pos+1);
console.log(x);

you can also use this function

function replace_last_comma_with_and(x) {
    var pos = x.lastIndexOf(',');
    return x.substring(0, pos) + ' and ' + x.substring(pos + 1);
}
console.log(replace_last_comma_with_and('a,b,c,d'));

An alternative solution using regex:

function replaceLastCommaWith(x, y) {
  return x.replace(/,(?=[^,]*$)/, " " + y + " ");
}
console.log(replaceLastCommaWith("a,b,c,d", "and")); //a,b,c and d
console.log(replaceLastCommaWith("a,b,c,d", "or")); //a,b,c or d

Solution 2

This regex should do the job

"a,b,c,d".replace(/(.*),(.*)$/, "$1 and $2")

Solution 3

Try the following

var x= 'a,b,c,d';
x = x.replace(/,([^,]*)$/, " and $1");