What does sizeof mean in C language?

sizeof operator gets the memory footprint of a specified type or expression, in bytes. For example: int a occupies 4 bytes, float b occupies 4 bytes, and double c occupies 8 bytes.

The role of sizeof operator

sizeof operator is a unary operator in C language, used to obtain The memory footprint of the specified type or expression, in bytes.

Syntax

<code>sizeof(type)</code>

Among them:

• type: Specifies the type or expression to obtain the memory size.

Return value

The sizeof operator returns a value of type size_t, which represents an unsigned integer type large enough to store the size of any object.

Example

<code class="c">int a;
float b;
double c;

printf("int a: %lu bytes\n", sizeof(a));
printf("float b: %lu bytes\n", sizeof(b));
printf("double c: %lu bytes\n", sizeof(c));</code>

Output:

<code>int a: 4 bytes
float b: 4 bytes
double c: 8 bytes</code>

As can be seen from the output, different types of variables occupy different memory sizes.

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