c ++ sizeof（array）返回数组的声明长度的两倍 [英] c++ sizeof(array) return twice the array's declared length

问题描述

我有一段代码，其中两个数组声明为大小6和13，但是当使用'sizeof（）'时，长度返回为12和26.

I have a section of code in which two array are declared with sizes of 6 and 13, but when 'sizeof()' is used the lengths are returned as 12 and 26.

#include <iostream>
using namespace std;

int main(){

    enum charRaces {DWARF,ELF,GNOME,HALFELF,HALFLING,HUMAN};
    enum classes{WARRIOR,FIGHTER,RANGER,PALADIN,WIZARD,MAGE,ILLUSIONIST,PRIEST,CLERIC,DRUID,ROGUE,THEIF,BARD};

    short int races[6] = {DWARF,ELF,GNOME,HALFELF,HALFLING,HUMAN};
    short int classes[13] = {WARRIOR,FIGHTER,RANGER,PALADIN,WIZARD,MAGE,ILLUSIONIST,PRIEST,CLERIC,DRUID,ROGUE,THEIF,BARD};

    cout << "sizeof(races)\t"  << sizeof(races) << endl;
    cout << "sizeof(classes)\t"  << sizeof(classes) << endl;

    system("pause");

    return(0);
}

推荐答案

sizeof 返回变量的大小（在本例中为您的数组），其中 sizeof（char）为1.由于 char 为一个字节宽， sizeof 返回变量的大小（以字节为单位）。由于每个 short int 在您的系统上有两个字节宽，所以其中6个数组的大小为12，而13个数组的大小为26。

sizeof returns the size of a variable (in this case, your arrays), where sizeof(char) is 1. Since a char is one byte wide, sizeof returns the size of the variable in bytes. Since each short int is two bytes wide on your system, an array of 6 of them will have size 12, and an array of 13 will have size 26.

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