CODEWITHSUNDEEP
carraysstringintlong-integer
plc
plc

Reputation: 33

Converting large string of numbers (14 digits) to integer or long in C

I have a string that contains a 14-digit number.

I want to convert the string to an int.

When I use atoi(stringName), I get the max 32-bit in limitation.

Example:

String1 contains "201400000000"

long long tempNum1;
tempNum1 = atoi(String1);
printf("%d",tempNum1);

Output is: 2147483647

How can I turn this string into a number? I want to compare it to other strings of numbers and find which is the largest. (I have three strings of 14-digit numbers, I want to find which is the smallest, which is the largest).

Upvotes: 3

Views: 1623

Answers (4)

Jibin Mathew
Jibin Mathew

Reputation: 5112

try 

 sscanf( String1, "%lld", &TempNum1);

Note that the format specifier %lld works for C99 , if not C99 please check the docs for the compiler

Upvotes: 1

Bathsheba
Bathsheba

Reputation: 234785

atoi returns an int.

That int is assigned to a long long, but by then the limit has already been reached.

You want to use atoll which returns a long long.

And your printf format specifier is incorrect for your type.

Upvotes: 3

Rahul Tripathi
Rahul Tripathi

Reputation: 172518

You can try like this using strol:

long strtol (const char *Str, char **EndPoint, int Base)

or

long long strtoll( const char *restrict str, char **restrict str_end, int base );

The atoi says:

The call atoi(str) shall be equivalent to:

(int) strtol(str, (char **)NULL, 10)

except that the handling of errors may differ. If the value cannot be represented, the behavior is undefined.

Upvotes: 1

melpomene
melpomene

Reputation: 85827

Since your target is a long long int, you can use the strtoll function:

#include <stdlib.h>

long long tempNum1 = strtoll(String1, NULL, 10);

Upvotes: 3

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