What does x- mean in c language?

There are four uses of the minus sign (-) in C language: 1. Subtraction operator (representing the difference between two numbers or expressions); 2. Unary operator (representing the difference between a number or expression) Negative value); 3. Pointer dereference operator (get the value pointed to at the address); 4. Structure or union member access operator (access the members of the structure or union).

What does x- mean in C language

In C language, there are many kinds of minus sign (-) Usage depends on its location and context.

1. Subtraction operator

The most common use is as a subtraction operator, expressing the difference between two numbers or expressions. For example:

<code class="c">int x = 10 - 5; // x 的值为 5</code>

2. Unary operator (negation)

When the minus sign is placed in front of a number or expression, it becomes a unary operator. Represents the negative value of the number or expression. For example:

<code class="c">int x = -10; // x 的值为 -10</code>

3. Pointer dereference operator (get address)

When the minus sign is placed in front of a pointer, it means to perform the operation on the memory address pointed to. Dereference to obtain the value at that address. For example:

<code class="c">int* ptr = &x;
int value = *ptr; // value 的值为 10</code>

4. Structure or union member access operator

When the minus sign is placed after a structure or union, followed by a member name, It indicates access to the member. For example:

<code class="c">struct MyStruct {
    int x;
    int y;
};
MyStruct s;
int x = s.x; // x 的值为 10</code>

Note: In C language, the minus sign (-) is different from the subtraction operator (-). The latter is a binary operator and requires two operands, while the former can be a unary or binary operator depending on its location and context.

The above is the detailed content of What does x- mean in c language?. For more information, please follow other related articles on the PHP Chinese website!