What does size of mean in C language?

sizeof operator is used to return the size (in bytes) of the specified data type or variable. Purpose: Determine storage space requirements of data types Create portable code Dynamic memory allocation

The meaning of sizeof in C language

sizeof is an operator in C language that returns the size (in bytes) of a specified data type or variable.

Usage:

##sizeof(type/variable_name);

Example:

<code class="c">int x;
printf("x 的大小：%d 字节\n", sizeof(x)); // 结果：4 字节（int 类型的大小）</code>

Purpose:

sizeof operator has many uses in C language programming, including:

• Determine the storage of data type Space requirements: Helps reserve memory and manage storage space efficiently.
• Create portable code: On different platforms, the storage space requirements of different data types may be different. Use sizeof to automatically adjust the size of data types in your code so that it can run on multiple platforms.
• Dynamic memory allocation: By determining the memory size of an object, the correct amount of memory can be allocated using functions such as malloc() and calloc().

Note:

sizeof returns the original size of the variable or type, excluding any alignment or padding bytes.
• sizeof(type) returns the number of bytes of the type, while sizeof(variable_name) returns the number of bytes of the variable instance.
• For arrays, sizeof returns the number of bytes occupied by the entire array, not the size of a single element.

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