JSFiddle - React, Tailwind, and code Playground

JavaScript

var string = 'This is a text that needs to change';
    var array1 = ['a', 'e', 'i', 'o', 'u'];
    var array2 = ['1', '2', '3', '4', '5'];
    
    var a = string.split('');
    a.map(function(c) {
    	if (array1.indexOf(c) != -1) {
    		a[ a.indexOf(c) ] = array2[ array1.indexOf(c) ];
    	}
    });
    
    var newString = a.join('');
    alert( newString );