JAVA进阶5

间歇性混吃等死，持续性踌躇满志系列-------------第5天

1、IDEA常用快捷键

2、简单方法的使用

package cn.intcast.day05.demo01;

public class demo01 {
    public static void main(String[] args) {
        //单独调用
        sum(3, 4);
        //打印调用
        System.out.println(sum(5, 9));
        //赋值调用
        int num = sum(100, 12);
        System.out.println("赋值后变量的值：" + num);
    }

    public static int sum(int a, int b) {
        int re = a + b;
        return re;
    }
}

运行结果图

3、方法中有参数和无参数的对比

package cn.intcast.day05.demo01;

public class demo01 {
    public static void main(String[] args) {
        me(12,12);
        we();
    }

    //有参数
    public static void me(int a, int b) {
        int re = a * b;
        System.out.println("两数的积" + re);
    }
    //无参数
    public static void we(){
        for (int i = 0; i < 5; i++) {
            System.out.println("你好啊！");
        }
    }
}

运行结果图

4、方法练习：比较两个数字是否相等

package cn.intcast.day05.demo01;

//判断两个数是否相等
public class demo01 {
    public static void main(String[] args) {
        System.out.println(isSame(10, 15));  //false
        System.out.println(isSame(10, 10));  //true
    }

    /*三要素
    返回值：boolean
    方法名称：isSame
    参数列表：int a ,int b
    */
    public static boolean isSame(int a, int b) {
        /*boolean same;
        if(a==b){
            same =true;
        }else {
            same =false;
        }
        return same;*/

        /*boolean same = a==b? true:false;
        return same;*/
        return a == b;
    }
}

运行结果图

5、使用方法的注意事项

6、方法的重载

package cn.intcast.day05.demo01;

//判断两个数是否相等
public class demo01 {
    public static void main(String[] args) {
        byte a = 10;
        byte b = 10;
        System.out.println(su(a, b));
        System.out.println(su((short) 11, (short) 12));
        System.out.println(su(12, 1));
        System.out.println(su(1l, 2L));
    }

    public static boolean su(byte a, byte b) {
        System.out.println("两个byte参数的执行！！！");
        return a == b;
    }

    public static boolean su(short a, short b) {
        System.out.println("两个short参数的执行！！！");
        if (a == b) {
            return true;
        } else {
            return false;
        }
    }

    public static boolean su(int a, int b) {
        System.out.println("两个int参数的执行！！！");
        boolean s;
        if (a == b) {
            s = true;
        } else {
            s = false;
        }
        return s;
    }

    public static boolean su(long a, long b) {
        System.out.println("两个long参数的执行！！！");
        boolean s = a == b ? true : false;
        return s;
    }
}

运行结果图