Why are the last row and last column behaving like this? - c

Question

I am a complete beginner to c programming. Help me out please. I am trying to write a program that reads from a .txt file and stores the values in a 2D array and later it prints the array to show what it got.
This is what is contained in my .txt file:
100 200 300
400 500 600
This is the program I have written:
#include <stdio.h>
main(){
//reading file
FILE *fp;
fp=fopen("c:\\users\\user\\desktop\\Arpon 4-1\\Thesis Programming\\Nov18-1.txt", "r");
//creating a 2d array
float a[9][9]={0};
//getting the data into the array
int r,c;
for(r=0; r<=1; r++){
for(c=0; c<=2; c++){
fscanf(fp, "%f", &a[r][c]);
}
}
//printing the array
for(r=0; r<=9; r++){
for(c=0; c<=9; c++){
printf("%.0f ", a[r][c]);
}
printf("\n");
}
}
The program does what I intend it to do, but the output comes out like this:
100 200 300 0 0 0 0 0 0 400
400 500 600 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 1990463982126334400000000000000000
1990463982126334400000000000000000 0 0 0 0 0 0 0 0 0
Why are the last column and row behaving like this? a[0][9], a[8][9] and a[9][0] should all be zeros as I initiated the whole array as 0 in line 8. But they are not. This is bugging me out a lot. Please help!
p.s. If I write float a[9][9]; instead of float a[9][9]={0}; , the output is worse. But this should have worked too, as I understand, because any array should be initiated as 0s by default.
The output in this case is like this:
100 200 300 0 0 0 0 0 0 400
400 500 600 0 0 0 0 -144118967647076350 0 0
0 3508856861431739000000000000000000 2070380395102208 0 0 0 0 -0 0 1921062897128927200000000000000000
1921062897128927200000000000000000 0 0 0 0 0 -0 0 1921062897128927200000000000000000 0
0 0 1921064599296481200000000000000000 -0 0 0 3501549920349857000000000000000000 3486704852883756600000000000000000 -1 0
0 0 0 0 -5529745792027328500 0 0 0 0 1931126885420802600000000000000000
1931126885420802600000000000000000 0 0 1941291301598365100000000000000000 1990334617392229100000000000000000 0 1940873342092601300000000000000000 0 1931097793829879400000000000000000 1931096401147335200000000000000000
1931096401147335200000000000000000 -0 0 0 0 0 0 0 0 1934835908521006500000000000000000
1934835908521006500000000000000000 -406541672906752 -1 1931096401147335200000000000000000 1931134003576028500000000000000000 0 0 0 0 1990463982126334400000000000000000
1990463982126334400000000000000000 0 0 0 0 0 0 0 0 0
The first 6 values are okay, but the other stuff, oh well :(

Answer 1

#include <stdio.h>
main(){
//reading file
FILE *fp;
fp=fopen("c:\\users\\user\\desktop\\Arpon 4-1\\Thesis Programming\\Nov18-1.txt","r");
//creating a 2d array
float a[9][9]={0};
//getting the data into the array
int r,c;
for(r=0; r<=1; r++){
for(c=0; c<=2; c++){
fscanf(fp, "%f", &a[r][c]);
}
}
//printing the array
for(r=0; r<9; r++){
for(c=0; c<9; c++){
printf("%.0f ", a[r][c]);
}
printf("\n");
}
}
The problem is in printing the array. You have declared a[9][9] but trying to print the 10 row and column , so there is a junk value . Execute the above program and get your expected output