雖然循環更改字符串變量

Question

作爲c編程的新手（我只有視覺基本經驗），我不完全確定如何在條件語句中更改字符串變量的while循環應該如何工作。

下面的代碼是一個簡單的計算器，我可以讓用戶輸入一個操作和兩個數字，然後輸出相應的結果。我試圖在一個while循環中進行編碼，這個循環不斷重複這個過程，直到用戶決定退出它。但似乎行scanf（「％c」，&退出）;不會影響while循環條件語句。

#include <stdio.h> 

int main() { 
float num1, num2; 
char operation; 
char quit = "n"; 
while (quit = "n"){ 
printf("Enter an operator (+, -, *, /) \n"); 
scanf(" %c", &operation); 
printf("Enter the numbers you wish to carry out the operation on \n"); 
scanf("%f %f", &num1, &num2); 
    switch(operation) { 
     case '+': 
      printf("%f\n", num1+num2); 
      break; 
     case '-': 
      printf("%f\n", num1-num2); 
      break; 
     case '*': 
      printf("%f\n", num1*num2); 
      break; 
     case '/': 
      printf("%f\n", num1/num2); 
      break; 

    } 
printf("Would you like quit the program, is so enter 'y' \n"); 
scanf("%c", &quit); 
} 
return 0; 
} 

感謝您提前給予的所有幫助。

Answer 1

那是因爲你是在爲你而循環分配的，而不是檢查其價值的退出變量的值，更換while (quit = "n")。

使用==爲=

while(quit == "n"){...} 

Answer 2

與while (quit! = 'y')

Answer 3

你可以做這樣的

#include <stdio.h> 
int main() { 
float num1, num2; 
char operation; 
char quit = 'n'; 
//while (quit = "n") // 
    while (quit!= 'y') 
{ 
printf("Enter an operator (+, -, *, /) \n"); 
scanf(" %c", &operation); 
printf("Enter the numbers you wish to carry out the operation on \n"); 
scanf("%f %f", &num1, &num2); 
switch(operation) { 
    case '+': 
     printf("%f\n", num1+num2); 
     break; 
    case '-': 
     printf("%f\n", num1-num2); 
     break; 
    case '*': 
     printf("%f\n", num1*num2); 
     break; 
    case '/': 
     printf("%f\n", num1/num2); 
     break; 

} 
printf("Would you like quit the program, is so enter 'y' \n"); 
scanf("%c", &quit); 
} 
return 0; 
}