StringImmuabilityTraining.java

public class StringImmuabilityTraining {
    
    public static void main(String[] args) {
        // String are immuable
        String foo = "John";
        String foo2 = foo;
        foo += "Toto";
        System.out.println(foo); // "JohnToto"
        System.out.println(foo2); // "John"

        // StringBuilder are muable
        StringBuilder sb = new StringBuilder("John");
        StringBuilder sb2 = sb;
        sb.append("Toto");
        System.out.println(sb2); // "JohnToto"
        System.out.println(sb2); // "JohnToto"
    }
}