Non-static method calls static method - how is it possible?

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Hi, how is it possible that: as method2() is non-static, method1() cannot use it => method1() needs to be static as well. So why in method2() that is changed to static I can call non-static method3()? What exactly 'new Solution().method3()' works like? Could anybody explain it to me in an easy way, please?

public static void method1() {
        method2();
    }

    public static void method2() {
        new Solution().method3();
    }

    public void method3() {
        method4();
    }

    public void method4() {
        step++;

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Guadalupe Gagnon

Poziom 37 , Tampa, United States

22 marca 2022, 17:16

static means that it is object independent. You can call static methods or fields without creating a new object. Non-static methods/fields require an object to be used. On line 6 a new Solution object is created which is then used to call method3(). You can do this and it would be the same as creating a variable, initializing it with a new object of the Solution class, and then calling method3() as shown below:

Solution temp = new Solution(); // create variable and initialize
temp.method3(); // call method3()

Because method3() is not static it MUST be called with an object like line 6 does. Also, because non-static methods MUST be called with an object, there is ALWAYS guaranteed to be an object associated with the method call. Therefore non-static methods can call other non-static methods. So while line 6, inside the static method2() has to create a new object to call the non-static method3(); however line 10 that is inside the non-static method3() can call the non-static method4() without creating a new object. So, to put simply, though it may not make a lot of sense without practice: 1) static methods/fields are object independent and can be used without an object 2) non-static methods/fields MUST be called using an object 3) in static methods, the non-static methods/fields will need an object to access 4) in non-static methods the static methods/fields can be accessed without any objects

Monika

Poziom 15 , Poland

19 kwietnia 2022, 15:45

Thanks a lot!