Question

我正在学习如何返回一个值并尝试编写以下代码;

public class JustTryingReturn {

static int a, b;
static Scanner sc = new Scanner(System.in);
static int nganu() {
return a+b;
}

public static void main(String[] args) {
    int c = nganu();
    System.out.println("Enter number ");
    a = sc.nextInt();
    b = sc.nextInt();
    System.out.println(c);
}

}

但输出始终打印0而不是a+b。我做错了什么？谢谢。

Answer 1

你应该拨打电话

int c = nganu();

分配a和b的输入值后。否则，在计算总和时，默认情况下它们仍会包含0。

System.out.println("Enter number ");
a = sc.nextInt();
b = sc.nextInt();
int c = nganu();
System.out.println(c);

Answer 2

尝试使用此更改此行的顺序：

 int c = nganu();
 a = sc.nextInt();
 b = sc.nextInt();

喜欢这个：

 public class JustTryingReturn {
  static    int a, b;

 static Scanner sc = new Scanner(System.in);
 static  int nganu() {
 return a+b;
}

 public static void main(String[] args) {

  // the order was changed
   System.out.println("Enter number ");
    a = sc.nextInt();  
    b = sc.nextInt();   
   int c = nganu();
System.out.println(c);
 }  

  }

Answer 3

您必须在之后调用您的函数，并将值分配给a和b。
所以在得到int c = nganu();和a后，请将此b。

Answer 4

请相应更改您的代码，

public static void main(String[] args) {
    //int c = nganu(); // here first time a,b is 0, still you haven't assign...
    System.out.println("Enter number ");
    a = sc.nextInt(); // now, actually you have assign value to a
    b = sc.nextInt(); // now, actually you have assign value to b
    int c = nganu();
    System.out.println(c);
}

返回一个值。输出始终打印0

4 个答案: