JS - replace character

Question

//Replaces all spaces with '-'!
city_name=city_name.replace(/ /gi,'-');

Answer 1

var text = "I love you no matter what";
var new_text = text.replace("love", "hate");
document.write(new_text);

Answer 2

var str="Test:";
document.write(str.replace(/:/g, ""));