[qiqinuinaifen128]

if i have a string, how do i check whether the string is number?

[technosavvy]

look for atoi() function...
it will return zero if it is not able to convert the string passed into number..

though if you have an alphanumeric inputs (like 1234go4expert)..u should go for strtol()..

both the functions even convert the input passed into their respective numbers(if possible).

[Salem]

You should use strtol() all the time.
atoi() for example cannot detect numeric overflow.

[technosavvy]

completely agree..
there is another kind of case ..when input is "1234forum"
atoi() will return 1234..!!

and in case of strtol() using the third argument we can check if the function traversed the whole input or not..

[qiqinuinaifen128]

Thank you so much. I will try it