[C++]cpp小筆記3 --- C++數組, 數組指針

1. 聲明

數組的聲明遵循一下格式：

typeName arrayName[arraySize];  

2.初始化

數組的賦值規則：

• 只能在聲明的時候初始化

int cards[4] = {3, 6, 8, 10}; //okay

cont int size = 4;
int pics[size] ={3, 6, 8, 10}; //okay
int numbers = 4;
int pics[numbers] = {3, 6, 8, 10};   //not allowed
int pictures[] = {1, 2, 3, 4}; //okay  
int hand[4]; //okay  
hand[4] = {5, 6, 7, 9}; //not allowed   

hand = cards; //not allowed
先聲明，過後單個元素初始化
 int array2[4];  
int array2size = sizeof(array2) / sizeof(int);  
    for (int i = 0; i < array2size; i ++) {  
        array2[i] = 0;  
    }
不全賦值
float hotelTips[5] = {5.0, 2.5};  //剩餘的3被編譯器設爲0 
float lunchMoney[100] = {}   //全部被編譯器初始化爲0

數組指針

int * ipa = new int[3];
*ipa = 1;  
ipa[0] = 2; 
*(ipa+1)=3;  
ipa[2] = 4;
cout<<*ipa << " " <<ipa[0] << " "<< *(ipa+1) <<" "<<ipa[2]<<endl;
Result is 2 2 3 4

數組對象

std::array<double, 4> doubleArray = {1,2,3,4};

double類型的4個容量的數組對象doubleArray.

當數組對象作爲參數傳遞給函數時，數組對象是作爲值傳遞的。