C++基础知识（二）数组

• 一维数组初始化

int a[10] = {1,2,3,4} //a={1,2,3,4,0,0,0,0,0,0}

随机初始化

#include "iostream.h"
#include "stdlib.h"
#include "time.h"
int main(int argc, char* argv[])
{
    int y[10];
    srand(time(0)); //
    for(int i=0;i<10;i++){
        y[i] = rand()%100; //
        cout<<y[i]<<' ';
    }
return 0;
}

• char数组

char a[100], b[100]; 
scanf("%s", a); //输入“How are you” 
printf("%s", a); //输出“How” 
gets(b); //输入“How are you” 
puts(b); //输出“How are you”

char b[100]; 
strcpy(b,"hello word"); //可以
char a[]="hello word"; //可以
printf("%d %d %d %d",sizeof(a), sizeof(b), strlen(a), strlen(b)); // 11 100 10 10
b="hello word"; //错误！！！

printf("%d", strlen("abcd\b\123\xab")); // 7，“abcd”4字节，“\b”+“\123”+“\xab”3字节

 下面代码输出为0 1，a\b是地址不同的数组，c\d指向同一个数组。

#include "iostream"
using namespace std;
int main(){
    char a[]="aaa";
    char b[]="aaa";
    char *c="aaa";
    char *d="aaa";
    cout<<bool(a==b)<<" "<<bool(c==d)<<endl;
    return 0;
}