It is allowed to perform the operation module % with double number in java, and how to change a single position of a string in java?

Question

My doubts..

• It is allowed to perform the operation module % with floating point number in java, and why? Because in compilers like c++ this operation is not allowed.

• How do I access an element of a string and change it ? Example, I have a string. String s = "ola"; How to change the position 0 of the element by a letter or scale ?

• It is allowed to access a String as an array ? example str[i].

Answer 1

1:

class Teste {
    public static void main(String[] args) {
        System.out.println(6.25 % 2.5);
    }
}

Output: 1.25.

2: Strings are immutable! That is, you would have to create a new String instead of changing the existing one. For example:

String s = "ola";
String s2 = "x" + s.substring(1);
System.out.println(s2);

The exit is xla.

3: No. But you can do something like this:

String s = "teste";
char[] array = s.toCharArray();
array[2] = 'x';
String s2 = new String(array);