CODEWITHSUNDEEP
carrays
user3054399
user3054399

Reputation: 13

Check that an array contains only numbers

I'm having a problem where I am wanting to go through an array and check that only positive numbers have been entered. I know that it is possible to use isDigit from ctype.h but I'd rather construct something myself. The way I think it is possible, is to iterate through each element of the array and see if the value stored there is between 0 and 9, but it isn't working. This is my code so far: 

char testArray[11] = {'0'};  
printf("Enter a string no longer than 10 chars");  
scanf("%s", testArray);  
int x;  
int notanumber = 0;  
for (x = 0; x < 11; x++) {  
        if ((testArray[x] < 0) || (testArray[x] > 9)) {  
                notanumber++;  
        }  
}  
printf("%i", notanumber);

Upvotes: 1

Views: 1418

Answers (2)

haccks
haccks

Reputation: 106012

It is not working because 0 and 9 are integers not characters. Change your if condition to 

if((testArray[x] >= '0') || (testArray[x] <= '9')){ ... }

to check the digits from 0 to 9.

Upvotes: 1

MOHAMED
MOHAMED

Reputation: 43518

this line

if((testArray[x] < 0) || (testArray[x] > 9)){

should be replaced by

if((testArray[x] < '0') || (testArray[x] > '9')){

Upvotes: 0

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