java值传递、引用传递

public static void main(String[] args) {
        int num = 10;
        foo(num);
        System.out.println(num);

        String num1 = "10";
        foo(num1);
        System.out.println(num1);

        StringBuilder sb = new StringBuilder("iphone");
        foo(sb);
        System.out.println(sb);

        StringBuilder sb1 = new StringBuilder("iphone");
        foo1(sb1);
        System.out.println(sb1);
    }

    static void foo(int value) {
        value = 100;
    }

    static void foo(String text) {
        text = "windows";
    }

    static void foo(StringBuilder builder) {
        builder.append("4");
    }

    static void foo1(StringBuilder builder) {
        builder = new StringBuilder("ipad");
    }