JSFiddle - React, Tailwind, and code Playground

by dmelnik

JavaScript

function func(s, a, b) {

	if (s.match(/^$/)) {
		return -1;
	}
	
	var i = s.length -1;
	var aIndex =     -1;
	var bIndex =     -1;
  
	while (i >= 0) {
	    if (s.substring(i, i +1) == a) {
	    	aIndex = i;
    	}
	    if (s.substring(i, i +1) == b) {
	    	bIndex = i;
    	}
	    i = i - 1;
	}
	
	if (aIndex != -1) {
	    if (bIndex == -1) {
	        return aIndex;
	    }
	    else {
	        return Math.max(aIndex, bIndex);
	    }
	}
	
	if (bIndex != -1) {
	    return bIndex;
	}
	else {
	    return -1;
	}
}

console.log(
func('hello world', 'l', 'o'),
func('hello world', '', undefined),
)