Variable parameters

Variable parameters

1. In the method declaration , An ellipsis after the specified parameter type （…）.
2. Only one variable parameter can be specified in a method , And it must be the last parameter of the method . Any ordinary parameter must be declared before it .

Code example 1

package method;

public class Demo04 {
    
    public static void main(String[] args) {
    
        Demo04 demo04 = new Demo04();
        demo04.test(1,2,3,5,56);
    }
    public void test(int... i){
    
        System.out.println(i[0]);
        System.out.println(i[1]);
        System.out.println(i[2]);
        System.out.println(i[3]);
        System.out.println(i[4]);
    }
}

Operation result display

D:\apps\jdk8\bin\java.exe "-javaagent:E:\javanote\IntelliJ IDEA Community Edition 2021.1\lib\idea_rt.jar=53572:E:\javanote\IntelliJ IDEA Community Edition 2021.1\bin" -Dfile.encoding=UTF-8 -classpath D:\apps\jdk8\jre\lib\charsets.jar;D:\apps\jdk8\jre\lib\deploy.jar;D:\apps\jdk8\jre\lib\ext\access-bridge-64.jar;D:\apps\jdk8\jre\lib\ext\cldrdata.jar;D:\apps\jdk8\jre\lib\ext\dnsns.jar;D:\apps\jdk8\jre\lib\ext\jaccess.jar;D:\apps\jdk8\jre\lib\ext\jfxrt.jar;D:\apps\jdk8\jre\lib\ext\localedata.jar;D:\apps\jdk8\jre\lib\ext\nashorn.jar;D:\apps\jdk8\jre\lib\ext\sunec.jar;D:\apps\jdk8\jre\lib\ext\sunjce_provider.jar;D:\apps\jdk8\jre\lib\ext\sunmscapi.jar;D:\apps\jdk8\jre\lib\ext\sunpkcs11.jar;D:\apps\jdk8\jre\lib\ext\zipfs.jar;D:\apps\jdk8\jre\lib\javaws.jar;D:\apps\jdk8\jre\lib\jce.jar;D:\apps\jdk8\jre\lib\jfr.jar;D:\apps\jdk8\jre\lib\jfxswt.jar;D:\apps\jdk8\jre\lib\jsse.jar;D:\apps\jdk8\jre\lib\management-agent.jar;D:\apps\jdk8\jre\lib\plugin.jar;D:\apps\jdk8\jre\lib\resources.jar;D:\apps\jdk8\jre\lib\rt.jar;E:\javanote\out\production\Hello method.Demo02
 The maximum number is ：56

Process finished with exit code 0

Code example 2

package method;

public class Demo02 {
    
    public static void main(String[] args) {
    
        bigger(23.2,56.3,89.7,56,100.5);
        bigger(new double[]{
    90,2.3,8.4,4.9});

    }
    public static void bigger(double...numbers){
    

        if (numbers.length==0){
    
            System.out.println("no numbers");
            return;
        }
        double a=numbers[0];
        // Sort 
        for (int i=1;i<numbers.length;i++){
    
            if (a<numbers[i]){
    
                a=numbers[i];
            }
        }
        System.out.println(" The maximum number is ："+a);

    }
}

Operation result display

```bash
D:\apps\jdk8\bin\java.exe "-javaagent:E:\javanote\IntelliJ IDEA Community Edition 2021.1\lib\idea_rt.jar=53572:E:\javanote\IntelliJ IDEA Community Edition 2021.1\bin" -Dfile.encoding=UTF-8 -classpath D:\apps\jdk8\jre\lib\charsets.jar;D:\apps\jdk8\jre\lib\deploy.jar;D:\apps\jdk8\jre\lib\ext\access-bridge-64.jar;D:\apps\jdk8\jre\lib\ext\cldrdata.jar;D:\apps\jdk8\jre\lib\ext\dnsns.jar;D:\apps\jdk8\jre\lib\ext\jaccess.jar;D:\apps\jdk8\jre\lib\ext\jfxrt.jar;D:\apps\jdk8\jre\lib\ext\localedata.jar;D:\apps\jdk8\jre\lib\ext\nashorn.jar;D:\apps\jdk8\jre\lib\ext\sunec.jar;D:\apps\jdk8\jre\lib\ext\sunjce_provider.jar;D:\apps\jdk8\jre\lib\ext\sunmscapi.jar;D:\apps\jdk8\jre\lib\ext\sunpkcs11.jar;D:\apps\jdk8\jre\lib\ext\zipfs.jar;D:\apps\jdk8\jre\lib\javaws.jar;D:\apps\jdk8\jre\lib\jce.jar;D:\apps\jdk8\jre\lib\jfr.jar;D:\apps\jdk8\jre\lib\jfxswt.jar;D:\apps\jdk8\jre\lib\jsse.jar;D:\apps\jdk8\jre\lib\management-agent.jar;D:\apps\jdk8\jre\lib\plugin.jar;D:\apps\jdk8\jre\lib\resources.jar;D:\apps\jdk8\jre\lib\rt.jar;E:\javanote\out\production\Hello method.Demo02
 The maximum number is ：100.5
 The maximum number is ：90.0

Process finished with exit code 0