Take random letters out from a string

Question

I want to remove 3 RANDOM letters from a string.

I can use something like substr() or slice() function but it won't let me take the random letters out.

Here is the demo of what I have right now.

http://jsfiddle.net/euuhyfr4/

Any help would be appreciated!

Answer 1

var str = "hello world";
for(var i = 0; i < 3; i++) {
    str = removeRandomLetter(str);
}
alert(str);

function removeRandomLetter(str) {
    var pos = Math.floor(Math.random()*str.length);
    return str.substring(0, pos)+str.substring(pos+1);
}

If you want to replace 3 random charc with other random chars, you can use 3 times this function:

function substitute(str) { 
    var pos = Math.floor(Math.random()*str.length); 
    return str.substring(0, pos) + getRandomLetter() + str.substring(pos+1); 
} 
function getRandomLetter() { 
    var  letters="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; 
    var pos = Math.floor(Math.random()*letters.length); 
    return letters.charAt(pos); 
}