Thread: Find specific number in array

I am trying to find the specific number in array. if user enter number ie 5 then program should be able to find that the number is present in array or not if it present in array then print number match and if its not in array then say it' invalid number

Code:

#include<stdio.h>int main ()
{
	int array[10], size, i, number;
	
	printf("Enter size : ");
	scanf("%d", &size);
	for(i = 0; i < size; i++)
	{
		printf(" \n Enter array element : ");
		scanf("%d",&array[i]);
	}
    
	printf("Enter number : ");
	scanf("%d", &number);
	number = array[0];
		
	for(i = 0; i < size; i++)
	{
		if (number == array[i])
		{
			printf(" \n Number match");
		}
		else
		{
			printf("\n Invalid Number");
		}
	}
	
	return 0;
}

why this program doesn't execute ?

Originally Posted by john.c

It executes for me. It doesn't give the right answer, of course, but it executes..

if i initialize variable i then it execute

number = array[0];

I am assuming first number of array is specif number and if it's not then compare with next index

Code:

#include<stdio.h>int main ()
{
    int array[10], size, number;
	int i = 0;
     
    printf("Enter size : ");
    scanf("%d", &size);
    for(i = 0; i < size; i++)
    {
        printf(" \n Enter array element : ");
        scanf("%d",&array[i]);
    }
     
    printf("Enter number : ");
    scanf("%d", &number);
    number = array[0];
         
    for(i = 0; i < size; i++)
    {
        if (array[i]== number)
        {
            printf(" \n Number match");
        }
        else
        {
            printf("\n Invalid Number");
        }
    }
     
    return 0;
}

Is there any simple method then the flag to display only true or false condition

There are lots of ways to do this but the way you've specifically chosen is incorrect, because what happens is
> number = array[0];
you assign array[0] to the input variable, making it impossible to remember what number the user typed.

I recommend something like the following.

Code:

int found = -1;
for (int idx = 0; idx < size; idx++) 
{
   if (array[idx] == number)
   {
      found = idx;
      break;
   }
}

found is either where the number is, or a -1 in case it isn't in the array at all.

Originally Posted by whiteflags

There are lots of ways to do this but the way you've specifically chosen is incorrect, because what happens is
.

If I do this, then both of statement's, if statement and else statement ​​will print because they will be under the for loop

Code:

#include<stdio.h>
int main (){
    int array[10], size, number, found;
     int i = 0;
    printf("Enter size : ");
    scanf("%d", &size);
    for(i = 0; i < size; i++)
    {
        printf(" \n Enter array element : ");
        scanf("%d",&array[i]);
    }
     
    printf("Enter number : ");
    scanf("%d", &number);
   
     found = -1;
     for (int i = 0; i < size; i++) 
    {
      if (array[i] == number)
      {
        found = i;
        break;
       }
    }
    return 0;
}

Thanks to all of you

Code:

#include<stdio.h>int main ()
{
    int array[10], size, number, found;
     int i = 0;
    printf("Enter size : ");
    scanf("%d", &size);
    for(i = 0; i < size; i++)
    {
        printf(" \n Enter array element : ");
        scanf("%d",&array[i]);
    }
     
    printf("Enter number : ");
    scanf("%d", &number);
   
     found = -1;
     for (int i = 0; i < size; i++) 
    {
      if (array[i] == number)
      {
        found = i;
        break;
       }
    }
	if (found ==1)
	{
	  printf("number is valid");
	}
	else
	{
		printf("number is invalid");
	}
    return 0;
}

Enter size : 4


Enter array element : 1


Enter array element : 2


Enter array element : 3


Enter array element : 4
Enter number : 5
number is invalid

Enter size : 4


Enter array element : 1


Enter array element : 2


Enter array element : 3


Enter array element : 4
Enter number : 2
number is valid

[QUOTE=vead;1277008] Try this!
It finds the number with its index

Code:

#include<stdio.h>

int main ()
{
    int array[10], size, i, number;
    int index = -1;
     
    printf("Enter size : ");
    scanf("%d", &size);
    for(i = 0; i < size; i++)
    {
        printf(" \n Enter array element : ");
        scanf("%d",&array[i]);
    }
     
    printf("Enter number : ");
    scanf("%d", &number);
         
    for(i = 0; i < size; i++)
    {
        if (number == array[i])
            index = i;
    }
    
    if(index != -1)
        printf("Number found at index %d",index);
     else
         printf("\n Invalid Number");
         
    return 0;
}