Function not returning expected value

Question

I've been practicing C for quite a few weeks now and I'm tryin to figure out what I might have done wrong in my code.

#include <stdio.h> #include <stdlib.h> #include <string.h> typedef struct accounts{ char unList[32]; int pinList; float amtList; }account; int isValid(char inputUN[], account acount[]); void initialize(account acount[], char unList[][10], int pinList[], float amtList[], int size); int main(int argc, char *argv[]) { int size = 10; account newAccs[size]; char unList[][10] = {"franklin", "woods", "phillips", "gomez", "burns", "porter", "griffin", "spencer", "hanson", "johnson"}; char inputUN[32]; int index; initialize(newAccs, unList, pinList, amtList, size); printf("Enter Username: "); scanf("%s", inputUN); index = isValid(inputUN, newAccs); printf("%d\n", index); return 0; } void initialize(account acount[], char unList[][10], int pinList[], float amtList[], int size){ int index; for(index = 0; index < size; index++){ strcpy(acount[index].unList, unList[index]); acount[index].pinList = pinList[index]; acount[index].amtList = amtList[index]; } } int isValid(char inputUN[], account acount[] ){ int index; int y; for(index = 0; index < 10; index++){ if (strcmp(acount[index].unList, inputUN ) == 0){ y = index; }else{ y= -1; } } return y; }

What I am really trying to do in this program is that the program is asking for a username input and Pin then it checks if both are in the structure and then it shows some amount, but i have ommitted the rest of the code since my problem is in the isValid() function...

 int isValid(char inputUN[], account acount[] ){ int index; int y; for(index = 0; index < 10; index++){ if (strcmp(acount[index].unList, inputUN ) == 0){ y = index; }else{ y= -1; } } return y; }

in this function it is supposed return the index of the element if the username is in the structure, else it returns -1. It works well if I placed comments in the else if statement. But if not, it always returns -1 even if I have input a correct element.

What might I have done wrong?

P.S. Sorry If my question was too long, I'm quite new to Stacks Overflow

have you tried to put a breakpoint to y=index to see if it ever got assigned a value? Also after being assigned you should break the loop or next one can reassign y to -1. — koksalb
– koksalb, Commented Mar 3, 2017 at 8:28

uzr · Accepted Answer · 2017-03-03 10:15:53Z

The problem was that you never exited the loop when you found the matching record.

int isValid(char inputUN[], account acount[] ){ int index; for(index = 0; index < 10; index++){ if (strcmp(acount[index].unList, inputUN ) == 0){ return index; // return directly } } return -1; }

MotKohn · Accepted Answer · 2017-03-03 06:03:33Z

Once you find the match you should break out of the for loop by adding a break; statement. Otherwise unless it matches the last option it will return -1. Like this:

int isValid(char inputUN[], account acount[] ){ int index; int y; for(index = 0; index < 10; index++){ if (strcmp(acount[index].unList, inputUN ) == 0){ y = index; break; }else{ y= -1; } } return y; }

or You can initialize y to -1 and test for it, like this:

int isValid(char inputUN[], account acount[] ){ int index; int y = -1; for(index = 0; index < 10 && y == -1; index++){ if (strcmp(acount[index].unList, inputUN ) == 0){ y = index; }else{ y= -1; } } return y; }

Your solution still doesn't work because it has the else clause still
@ChrisTurner it's definitely redundant, but should not have any negative effect it you break out before the next iteration.
Sorry - hadn't spotted you'd altered the for exit condition. It's just not as clearly readable as the other solution.

Collectives™ on Stack Overflow

Function not returning expected value

2 Answers 2

Comments

3 Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

3 Comments

Related