英文:
Why is this happening on my code although I did not return any value from a method?
问题
我写了一些Java代码；
int quantity = 0;
public void submitOrder(View view) {
displayMessage(createOrderSummary());
}
public void increment(View view) {
quantity = quantity + 1;
display(quantity);
}
public void decrement(View view) {
quantity = quantity - 1;
display(quantity);
}
private String createOrderSummary() {
String message = "数量： " + quantity;
return message;
}
这段代码正常工作。当我在应用程序上按+和-按钮时，它会执行增加和减少方法。但在这些方法中，我使用了void。我了解到这意味着该方法没有返回值。
那么，为什么这段代码可以正常工作，显示更改后的quantity变量呢？尽管更改是在一个没有返回语句的方法中进行的。
我认为它应该显示quantity为0，因为更改后的quantity值并未从这些方法中返回。我错在哪里了？
英文:
I wrote some Java code;
int quantity = 0;
public void submitOrder(View view) {
displayMessage(createOrderSummary());
}
public void increment(View view) {
quantity = quantity + 1;
display(quantity);
}
public void decrement(View view) {
quantity = quantity - 1;
display(quantity);
}
private String createOrderSummary() {
String message = "Quantity : " + quantity;
return message;
}
This code is working fine. When I press + and - buttons on app, it is executing increment and decrement methods. But in those methods, I used void. Which I learned that means "no return" on that method.
So, how can this code works as showing the quantity variable changed; although it was changed in a method which has no return statement?
I think it should show quantity as 0, because the changed quantity values were not returning from those methods. Where am I wrong?
答案1
得分: 1
实际上不返回整数并不意味着它不会应用更改（例如：递增 quantity = quantity + 1;）
void 表示在调用函数的地方不会返回任何值（例如，在不同的类中调用）。但是，如果调用它，它仍然会执行其中的代码。
英文:
Actually not returning the integer doesn't mean that it's not applying the change (e.g: incrementing quantity = quantity + 1; )
void means that no value will be returned to use in the place where the function is called (for an e.g in a different class). But if you call it, it will still execute the code inside it.
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