how to verify a string and double in c

Question

I'm new programming i started with c a month ago. I was writing code for my school homework and i was unable verify the gender and salary in the following code that i wrote. Can someone please help me with this.

Following is my question. Q3. A company decides to give bonus to all its employees on New Year. It is decided that 5% bonus will be given to all male employees and 10% bonus will be given to female employees.Further, if the salary of an employee is less than Rs. 10,000, then the employee gets an extra 2% bonus on salary. Write a C program to enter the salary and gender of an employee and calculate the bonus that has to be given to an employee.

following is my code.

int main()
{
 char gender[6];
 double salary;
 double bonusSalary;
 printf("enter your gender here:");
 scanf("%s", &gender);
 printf("enter your salary here:");
 scanf("%lf", &salary);
 if( gender == 'male' && salary<10000 )
 {
     bonusSalary=salary*(7.0/100.0);
 }
 else if( gender == 'male' )
 {
     bonusSalary=salary*(5.0/100.0);
 }
 else if( gender == 'female' && salary<10000 )
 {
     bonusSalary=salary*(10.0/100.0);
 }
 else if( gender == 'female' )
 {
     bonusSalary=salary*(12.0/100.0);
 }
 printf("bonus amount you will receive is:%f", bonusSalary);
 return 0;
}

The code i wrote reads gender and salary but whatever you type the bonus is displayed as zero it does not read the if and else if statements.

Please do not post code and text as images - [reasoning](https://meta.stackoverflow.com/questions/285551/why-not-upload-images-of-code-on-so-when-asking-a-question). Copy it as formatted text into the question. — kaylum, May 29 '21 at 11:43
Does this answer your question? [How do I properly compare strings in C?](https://stackoverflow.com/questions/8004237/how-do-i-properly-compare-strings-in-c) — kaylum, May 29 '21 at 11:43
Also, strings in C are terminated by a NUL (`'\0'`) character. This means a 6 character word like `"female"` requires a buffer of 7 chars. Storing past the end of a buffer results in Undefined Behaviour. — kaylum, May 29 '21 at 11:44
Did your compiler not produce warnings or errors when you compiled the code? I would have expected it to, but it's hard for me to verify since you didn't provide plain-text code in the question! — Paul Hankin, May 29 '21 at 11:47
Adding to @kaylum, in these cases it's better to represent things with numbers. A single int will suffice - 0 for male and 1 for female. Add on for other genders if that's part of the assignment as well. This is much more efficient and performant. — Shahe Ansar, May 29 '21 at 12:05

DadiBit · Answer 1 · 2021-06-12T08:23:10.977

C uses strings are an array of char (bytes raging from 0 to 255, each one corresponds to an ASCII character). To compare two string you can use strcmp() in the <string.h> library. C-strings are zero-terminated: it means that after the N character there's a 0:

+-------+-----+-----+-----+-----+-----+-----+-----+
| index |  0  |  1  |  2  |  3  |  4  |  5  |  6  |
+-------+-----+-----+-----+-----+-----+-----+-----+
| char  | 'f' | 'e' | 'm' | 'a' | 'l' | 'e' | NUL |
+-------+-----+-----+-----+-----+-----+-----+-----+

Please note: the final length is 7 character, if you consider this last "NUL", and not 6!

Btw, you are using a bad if-else logic. I suggest re-writing your code like this:

#include <stdio.h>
#include <string.h>

int main(){

    char gender[7]; //zero-terminated C-string
    double salary, bonusSalary;

    printf("enter your gender here:");
    scanf("%s", gender);

    printf("enter your salary here:");
    scanf("%lf", &salary);

    if ( strcmp(gender,"male")==0 ) {
        bonusSalary = salary<10000
          ? salary*(7.0/100.0);
          : salary*(5.0/100.0);
    } else if ( strcmp(gender,"female")==0 ) {
        bonusSalary = salary<10000
          ? salary*(10.0/100.0);
          : salary*(12.0/100.0);
    }

    printf("bonus amount you will receive is:%lf", bonusSalary);

    return 0;

}

PS: It's quite common for beginners to have difficulties with pointers, arrays, C-strings, etc. I know it's going to be boring, but it can really help to read carefully references like dummies or Tutorialspoint. In my opinion they're easy to understand and are a good place to start learning.

JASLP doesn't support the IES · Accepted Answer · 2022-05-10T18:17:06.153

I modified your code a bit, I guess this is what you're looking for

#include<stdio.h>
#include<string.h> //needs to be included to use strcmp()
int main(){
    char gender[7]; //gender needs to be of length 7 since "female" is of length 6 and it needs a null terminator at the end
    double salary;
    double bonusSalary;
    printf("enter your gender here:");
    scanf("%s", gender); //`gender` is already a pointer to a char, you don't need the &
    printf("enter your salary here:");
    scanf("%lf", &salary);
    if(strcmp(gender,"male")==0 && salary<10000 ) //strcmp() compares two strings, string literal in c needs to be in double quotes
    {
        bonusSalary=salary*(7.0/100.0);
    }
    else if(strcmp(gender,"male")==0)
    {
        bonusSalary=salary*(5.0/100.0);
    }
    else if(strcmp(gender,"female")==0 && salary<10000 )
    {
        bonusSalary=salary*(10.0/100.0);
    }
    else if(strcmp(gender,"female")==0)
    {
        bonusSalary=salary*(12.0/100.0);
    }
    printf("bonus amount you will receive is:%lf", bonusSalary);
    return 0;
}

how to verify a string and double in c

2 Answers2