C Program not entering for loop, but incrementing loop index variable?

Question

Here is the COMPLETE text of my program, besides what has been commented out:

#include <stdio.h>



int main (int argc, char* argv[] ){

   FILE* inFile = fopen(argv[1], "r");

   if(inFile==0){
      printf( "Error opening file, terminating program\n");
      return 1;
      }

   char* charArray = malloc(100*sizeof(char));

   int j=0;

   printf("%i", j);


   for(j=0; j++; j<100){
      printf("%c", charArray[j]);
      printf("%c", '\n');
      }


   printf("%i", j);

   return 0;
   }

I will call my program with the parameter text which is the name of a text file I want it to open. The part of my program that is commented out reads the text file into a character array, the same array I am trying to print in the for loop.

Right now, the char array contains complete garbage, but that's not the point--the point is, it's not outputting ANYTHING when it should at least be outputting SOMETHING!

Here is the output I am getting:

01

Somehow, j is being incremented exactly once, but I'm not even getting any endlines printed from within the for loop. What is going on?

It's clear that I have too much on my brain right now. This is such a ridiculous mistake that I'd like to know if it's a good idea to delete the question. I don't think it has much value in helping others. — Bobazonski
– Bobazonski, Commented Sep 17, 2014 at 4:50
Actually it helps, especially for the new users, this will teach them to never mess with order of things :) — chouaib
– chouaib, Commented Sep 17, 2014 at 4:57

nem035 · Accepted Answer · 2014-09-17 04:49:17Z

3

Your loop formatting is wrong.

The format for a for loop is:

for(INITIALIZATION; CONDITION; INCREMENT/DECREMENT){

}

You have the CONDITION and INCREMENT/DECREMENT mixed up

Change:

for(j=0; j++; j<100)

To:

for(j=0; j<100; j++)

answered Sep 17, 2014 at 4:49

nem035

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chouaib · Accepted Answer · 2014-09-17 04:49:08Z

3

change

for(j=0; j++; j<100)

to

for(j=0; j<100; j++)

answered Sep 17, 2014 at 4:49

chouaib

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Jayesh Bhoi · Accepted Answer · 2014-09-17 04:56:36Z

3

For your information

Useful syntax for for..loop is

for ( variable initialization; condition; variable update ) {
  Code to execute while the condition is true
}

So change your for..loop to

for(j=0; j<100; j++)

Also why separately print \n using printf("%c", '\n');. It should be enough like

printf("%c\n", charArray[j]);

edited Sep 17, 2014 at 4:56

answered Sep 17, 2014 at 4:49

Jayesh Bhoi

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Waqas Shabbir · Accepted Answer · 2014-09-17 04:56:45Z

1

Replace this

for(j=0; j++; j<100)

With this

for(j=0; j<100; j++)

answered Sep 17, 2014 at 4:56

Waqas Shabbir

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