Thread: The typical Largest smallest number printing

And the reason why you are not using a single variable to read input in and compare with min and max in a nice loop is?

One of the obvious issues is that you haven't initialised min and max before using them in a comparison.

Code:

if(a<min) //what is the value of min at this point?

Originally Posted by Fader_Berg

You should set min and max to zero. Otherwise they may contain garbage that mess up things.

What happens if someone enters in all positive integers?


[EDIT]

The second half of your statement is spot on though.

[EDITEDIT]

...or all negative integers.

Jannr, read common's code - you must initialise both max and min. If you don't initialise a variable before you use it, the behaviour will be undefined.

Thanks! I've solved it!

Here it is:

[Edit]

Code:

#include <stdio.h>
#include <conio.h>

int main()
{
    int a=0, b=0, c=0, d=0, e=0, min=0, max=0;
    
    // Ask values from the user and put values to min and max
    printf("Enter value of A: ");
    scanf("%d", &a);
    min = a;
    max = a;
    if(a<min)
    min = a;
    if(a>max)
    max = a;
    
    printf("Enter value of B: ");
    scanf("%d",&b);
    if(b<min)
    min = b;
    if(b>max)
    max = b;
    
    printf("Enter value of C: ");
    scanf("%d", &c);
    if(c<min)
    min = c;
    if(c>max)
    max = c;
    
    printf("Enter value of D: ");
    scanf("%d", &d);
    if(d<min)
    min = d;
    if(d>max)
    max = d;
    
    printf("Enter value of E: ");
    scanf("%d", &e);
    if(e<min)
    min = e;
    if(e>max)
    max = e;
    
    
    printf("Largest is: %d\n", max);
    printf("Smallest is: %d\n", min);
       
    getche();
}

Originally Posted by jannr

Btw, I solved the prob, I just have to initialize max and I did not initialize min as it will make min = 0 the smallest number thus cannot be changed with the users input.

Thanks all!!

Wrong... C does not initialize the values of variables declared inside a function (and main() is a function). Without initialization min and max will point to a memory location that will contain whatever garbage is left there by previous function calls. This is what they call "undefined behavior" and it is not to be trusted... It's the kind of thing that works well enough until the teacher is grading your papers, at which point you can be sure it will mess up... In the workplace the results can be catastrophic...

You should always manually initialize all variables to safe values before use.

Also... the correct form of main is... int main (void) ... and at the end it has to return a value (usually 0) to the operating system.

Originally Posted by bivhitscar

What happens if someone enters in all positive integers?


[EDIT]

The second half of your statement is spot on though.

[EDITEDIT]

...or all negative integers.

I don't get it... What happens?

[EDIT]

Ahhh...

Originally Posted by jannr

yes but if I also initialize min, the smallest will always be 0 if the user do not enter a negative number.

Read what I suggested...

Code:

#include <limits.h>

// inside main
int a = 0, b = 0, c = 0, d = 0, e = 0, min = INT_MAX, max = INT_MIN;

Look closely... everything is set to 0 so that should one of your scanf() calls fail (eg, user just presses enter) the garbage values they hold while uninitialized won't affect the outcome. Also min is preset to the highest number possible in an int and max is preset to the lowest this will force your first if statement to assign a value.

It is always a mistake to trust C to do anything for you... It's a complete idiot, you gotta tell it everything step by step.