輸入

package hello;

import java.util.Scanner;

public class Hello {

public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("Hello World");
Scanner in = new Scanner(System.in);
System.out.println(in.nextLine());
}

}

---------------------------------------------------

Scanner ：做輸入。

package hello;

import java.util.Scanner;

public class Hello {

public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("你好");
Scanner in = new Scanner(System.in);
System.out.println("echo:" + in.nextLine());
}

}

--------------------------------------------------------------

+ ：連接兩個字元串；其中一個可以是固定的，另一個可以像這個輸入的

package hello;

import java.util.Scanner;

public class Hello {

public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("你好");
// Scanner in = new Scanner(System.in);
// System.out.println("echo:" + in.nextLine());
System.out.println("2+3=" + 5);
}

}

------------------------------------------------------------

+ ：連接兩個字元串，其中一個是字元串，會將另一個轉化為字元串處理。

package hello;

import java.util.Scanner;

public class Hello {

public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("你好");
// Scanner in = new Scanner(System.in);
// System.out.println("echo:" + in.nextLine());
System.out.println("2+3="+5);
System.out.println("2+3="+2+3);
System.out.println("2+3="+(2+3));
System.out.println(2+3+"=2+3="+(2+3));
}

}

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() ：做計算，改變優先順序。