[javascript] How to globally replace a forward slash in a JavaScript string?

var str = '/questions'; // input: "/questions"
while(str.indexOf('/') != -1){
   str = str.replace('/', 'http://stackoverflow.com/');
}
alert(str); // output: "http://stackoverflow.com/questions"

The proposed regex /\//g did not work for me; the rest of the line (//g, replacement);) was commented out.