C 语言实例使用 sizeof 操作符计算int, float, double 和 char四种变量字节大小。
sizeof 是 C 语言的一种单目操作符，如C语言的其他操作符++、--等，它并不是函数。
sizeof 操作符以字节形式给出了其操作数的存储大小。
实例
#include <stdio.h> int main(){ int integerType; float floatType; double doubleType; char charType; // sizeof 操作符用于计算变量的字节大小 printf("Size of int: %ld bytes\n",sizeof(integerType)); printf("Size of float: %ld bytes\n",sizeof(floatType)); printf("Size of double: %ld bytes\n",sizeof(doubleType)); printf("Size of char: %ld byte\n",sizeof(charType)); return 0;}
运行结果：
Size of int: 4 bytesSize of float: 4 bytesSize of double: 8 bytesSize of char: 1 byte
计算 long long, long double 字节大小
实例
#include <stdio.h>int main(){ int a; long b; long long c; double e; long double f; printf("Size of int = %ld bytes \n", sizeof(a)); printf("Size of long = %ld bytes\n", sizeof(b)); printf("Size of long long = %ld bytes\n", sizeof(c)); printf("Size of double = %ld bytes\n", sizeof(e)); printf("Size of long double = %ld bytes\n", sizeof(f)); return 0;}
运行结果：
Size of int = 4 bytes Size of long = 8 bytesSize of long long = 8 bytesSize of double = 8 bytesSize of long double = 16 bytes