如何修复代码以删除字符串中的空格？

string = "Hello, World!"
string = string.replace(" ", "")
print(string)

let string = "Hello, World!";
string = string.replace(/ /g, "");
console.log(string);

String string = "Hello, World!";
String newString = "";
for (int i = 0; i < string.length(); i++) {
    if (string.charAt(i) != ' ') {
        newString += string.charAt(i);
    }
}
System.out.println(newString);

string = "Hello, World!"
new_string = string.gsub(/\s+/, "")
puts new_string