對(duì)于一個(gè)數(shù)組，sizeof  運(yùn)算符返回?cái)?shù)組元素的個(gè)數(shù)；但是如果把數(shù)組作為參數(shù)傳入一個(gè)函數(shù)就會(huì)發(fā)生指針降級(jí)，這時(shí)sizeof運(yùn)算符就會(huì)返回一個(gè)指針的大小

#include <stdio.h>#include <stdlib.h>void f(int array[]){    PRintf("%d/n",sizeof(array));}int main(){    int array[10];    printf("%d/n",sizeof(array)); ///輸出40    f(array); ///輸出4    int *arrayPoint = array;    printf("%d/n",sizeof(arrayPoint)); ///對(duì)于指針輸出為4    return 0;}