The role of sizeof function in c language

sizeof() function is used in C language to determine the memory size in bytes of a variable, data type, or expression. Its usage is as follows: size_t sizeof(const type-name | expression); and returns a value of size_t data type. The sizeof() function can be used to allocate the correct size of memory space, determine the size of an array or structure, and perform memory management.

The role of sizeof() function in C language

The role of sizeof() function

sizeof() function is used in C language as a unary operator to determine the memory size in bytes of a variable, data type, or expression.

Usage

sizeof() The syntax of the function is as follows:

<code class="c">size_t sizeof(const type-name | expression);</code>

Among them:

• type- name: The data type whose size is to be calculated.
• expression: The expression whose size is to be calculated.

Return type

sizeof() function returns a value of size_t data type, indicating the memory size of the calculated value.

Example

The following example shows how to use the sizeof() function:

<code class="c">int main() {
  int i = 10;
  printf("Size of int: %zu bytes\n", sizeof(i));
  printf("Size of int*: %zu bytes\n", sizeof(int *));
  return 0;
}</code>

The above code will output the following:

<code>Size of int: 4 bytes
Size of int*: 8 bytes</code>

In the first example, we calculated the size of the variable i, which is an integer, so the size is 4 bytes. In the second example, we calculated the size of the int * pointer variable, which is 8 bytes.

sizeof() function purpose

sizeof() function has many uses in C language, including:

• Correct allocation The size of the memory space.
• Determine the size of the array or structure.
• Perform memory management.
• Compare the sizes of different data types.

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