My program only takes input for the first prompt and it excludes the succeeding ones, and instead, it just directly prints them.

#include <stdio.h>

int main(){
    
    // Initialize
    char cCurrencyA, cCurrencyB;
    float fCurrencyA;
    float fRate;
    
    // Prompt user for currency names
    printf("Enter a currency name: ");
    scanf("%c%c", &cCurrencyA, &cCurrencyB);
    
    // Prompt user for the current rate
    printf("Enter the rate:");
    scanf("%f", &fRate);
    
    // Prompt user to enter value for currency A
    printf("Enter value for %c", cCurrencyA);
    scanf("%f", &fCurrencyA);
    
    // Convert currency A to B
    int nResult = fCurrencyA * fRate;
    
    // Print the result
    printf("%f%c is %d%c", fCurrencyA, cCurrencyA, nResult, cCurrencyB);
    return 0;
    
}

Output:

Enter a currency name:USD PHP
Enter the rate:
Enter value for U:
0.000000U is 0S

CodePudding user response：

1. so you have major problems , you are scanning a whole string into only one char , that's wrong , you should do char cCurrencyA[20], cCurrencyB[20]; not char cCurrencyA, cCurrencyB; to scan a string not only one char.

2. when you are scanning using scanf(), use the quantifier %s not %c , as %c will get only one character but %s will scan a whole string.

3. also to round the result , you could use math header file , by using the function called lround() , so do this int nResult = round((double)fCurrencyA * fRate); not int nResult = fCurrencyA * fRate; as the lValue is int while RValue is float so you have to cast it.

and here the code edited :

#include <stdio.h>
#include <math.h>
int main(){

    // Initialize
    char cCurrencyA[20], cCurrencyB[20];
    float fCurrencyA;
    float fRate;

    // Prompt user for currency names
    printf("Enter a currency name: ");
    scanf("s s", cCurrencyA, cCurrencyB);

    // Prompt user for the current rate
    printf("Enter the rate:");
    scanf("%f", &fRate);

    // Prompt user to enter value for currency A
    printf("Enter value for %s", cCurrencyA);
    scanf("%f", &fCurrencyA);

    // Convert currency A to B
    int nResult = lround((double)fCurrencyA * fRate);

    // Print the result
    printf("%f%s is %d%s", fCurrencyA, cCurrencyA, nResult, cCurrencyB);
    return 0;

}

and here is the output :

Enter a currency name:USD PHP
Enter the rate:10.5
Enter value for USD10
10.000000USD is 105PHP
Process finished with exit code 0

CodePudding user response：

First line of input was 8 characters: "USD PHP\n".

scanf("%c%c", &cCurrencyA, &cCurrencyB); only reads and saves the first 2 in cCurrencyA, cCurrencyB.

The remaining 6 are not numeric text for the next scanf("%f",... so it does not assign anything and returns 0. Same for the next scanf("%f",....

Best to read a line of user input with fgets() and then parse the string.

Yet if one must use the problematic scanf(), read currency names as a string.

// char cCurrencyA, cCurrencyB;
char cCurrencyA[100], cCurrencyB[100];

// scanf("%c%c", &cCurrencyA, &cCurrencyB);
scanf("