Why is array not printing?-CodePudding

I know its something simple but I cant figure out why my array is not printing once the user enters the size and integers. I finally was able to get the user to determine the size of the array and enter their own integers but now the program returns right after.

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

int main()
{
    //Declare a size variable
    int size = 0;
    
    //Ask user how many numbers are in list:
    printf("How many integers?");
    scanf("%d", &size);
    
    printf("Please enter integers:");
    int arr[size];
    scanf("%d", arr);
    
    //Calculate length of array
    int length = sizeof(arr)/sizeof(arr[0]);
    
    //Test print to see if array is returning the right amount of integers.
    //printf("%d", length);
    
    //Print original array
    for(int i = 0; i > length; i  )
    {
        printf("%d", arr[i]);
    }
    
    printf("\n");
    return 0;
}

CodePudding user response：

scanf("%d", arr);

Because arr now is a pointer to arr[0], scanf("%d", arr); will just input the first element of the array.

You have to put it in a for loop:

for(int i = 0; i < size;   i)
{
    scanf("%d", &arr[i]);
}

This for loop:

for(int i = 0; i > length; i  )
{
    printf("%d", arr[i]);
}

will never executed, because length is always larger than 0, so when i = 0, i > length is false.

You should use:

for(int i = 0; i < length; i  )
{
    printf("%d", arr[i]);
}

Also, length is just size, so you don't need length

So your code should be:

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

int main()
{
    int size = 0;
    
    printf("How many integers?");
    scanf("%d", &size);
    
    printf("Please enter integers:");
    int arr[size];

    for(int i = 0; i < size;   i)
    {
        scanf("%d", &arr[i]);
    }    

    for(int i = 0; i < size; i  )
    {
        printf("%d", arr[i]);
    }
    
    printf("\n");
    return 0;
}