爲什麼我的函數不返回一個字符串？

Question

我創建了一個函數（displayChoice）來生成一個隨機數，然後創建另一個函數（getComputerChoice）來獲取該數字並將該隨機整數賦值給一個字符串。當我打印該字符串時，什麼都不顯示。我失去了爲什麼會發生這種情況。

#include <iostream> 
#include <limits> 
#include <ctime> 
#include <cstdlib> 
int getComputerChoice(); 
std::string displayChoice(int dChoice); 


int main() 
{ 

std::string comp = displayChoice(getComputerChoice()); 
std::cout << comp; 
} 
int getComputerChoice() 
{ 
    srand(time(NULL)); 
    int ranCompChoice = (rand() % 6) + 1; 
    return ranCompChoice; 
} 


std::string displayChoice(int dChoice) 
{ 
std::string ChoiceString; 
if (dChoice == 1) 
{ 
    ChoiceString == "rock"; 

} 
else if (dChoice == 2) 
{ 
    ChoiceString == "paper"; 
} 
else if (dChoice == 3) 
{ 
    ChoiceString == "scissors"; 
} 
else if (dChoice == 4) 
{ 
    ChoiceString == "lizard"; 
} 
else 
{ 
    ChoiceString == "Spock"; 
} 
    return ChoiceString; 
} 

Answer 1

您必須使用賦值運算符。

例如 ChoiceString = "Spock";