What does !x mean in c language?

In C language, "!x" represents a logical NOT operation, which inverts the truth value of the operand: if the operand is true, it returns false, if it is false, it returns true. It is used in conditional statements to check if the condition is not true, thereby executing a different block of code.

In C language, "!x" represents a logical NOT operation.

The logical NOT operation is a unary operator, which operates on one operand. Its function is to invert the true value of the operand. In other words, if the operand is true, it returns false; if the operand is false, it returns true.

Syntax:

<code>!表达式</code>

For example:

<code class="c">int x = 5;

printf("x 为真：%d\n", x);
printf("!x 为假：%d\n", !x);</code>

Output:

<code>x 为真：1
!x 为假：0</code>

In this example, The value of x is 5, which is the true value. Performing a logical NOT operation on x inverts its value, producing a false value of 0.

Usage:

Logical NOT operations are often used in conditional statements, such as if and while loops. It can be used to check if a condition is not true, thereby executing a different block of code.

For example, the following code uses the logical NOT operation to check whether x is not equal to 5:

<code class="c">if (!x == 5) {
  printf("x 不等于 5\n");
}</code>

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!