如何从数组中选择指定索引以在 switch case 中使用它答案

【问题标题】：how can i select a specify index from an array to use it in switch case如何从数组中选择指定索引以在 switch case 中使用它
【发布时间】：2021-12-15 07:38:08
【问题描述】：

您好，我是初学者，我想制作一个数学问答游戏，如何选择随机数组的指定索引并将其用作案例值。

                Random random=new Random();
                int num1= random.nextInt(30);
                int num2= random.nextInt(30);
    
                System.out.println(num1+"+"+num2+"=");
                int result=num1+num2;
    
                System.out.println("What is the answer of this operation?");
    
              int sugg1=random.nextInt(100);
              int sugg2=random.nextInt(100);
          
                int[] array = {sugg1,sugg2,result};
        
                Random rand = new Random();
        
                for (int i = 0; i < array.length; i++) {
                    int randomIndexToSwap = rand.nextInt(array.length);
    
                    int temp = array[randomIndexToSwap];
    
                    array[randomIndexToSwap] = array[i];
    
                    array[i] = temp;
                }
                System.out.println(Arrays.toString(array));

                switch (Arrays.toString(array)) {
//I NEED HELP HERE HOW CAN I SELECT A SPECIFY INDEX OF THE RANDOM ARRAY AND USE IT AS CASE VALUE
               case array:
                
               }

【问题讨论】：

switch(array[someIndex]) { case 1: ... case 2: ... } ?
您实际上想通过使用开关来实现什么？

标签： java arrays random switch-statement

【解决方案1】：

您可以使用switch(array[yourIndex]){case element: ...}

【讨论】：

【解决方案2】：

我不确定你想做什么..

值版本：

// Print for example [14,21,30] if question is 10+11
System.out.println(Arrays.toString(array));
// You want the user to select the answer
System.out.print("Please type the good answer : ");
Scanner scan = new Scanner(System.in);
switch(scan.nextInt()){
    case result:
        System.out.println("Good answer!");
        break;
    default:
        System.out.printtln("Bad answer!");
}

索引版本：

// Print for example [14,21,30] if question is 10+11
System.out.println(Arrays.toString(array));
// You want the user to select the answer index
System.out.print("Please type the good answer : ");
Scanner scan = new Scanner(System.in);
int index = scan.nextInt();
if(index >= 0 && index <= array.length) {
    switch(array[index]){
        case result:
            System.out.println("Good answer!");
            break;
        default:
            System.out.printtln("Bad answer!");
    }
} else {
    System.out.println("Selected index does not exist in the array");
}

顺便说一句，如果sugg1 != sugg2 != answer 可能会很好，因为在下面的代码中，值相同并非不可能：

int sugg1=random.nextInt(100);
int sugg2=random.nextInt(100);
int[] array = {sugg1,sugg2,result};

【讨论】：