Precautions for intvalue in oC

In the program, I found a problem and wrote an example, as shown below:

Nsdictionary * dict = [[nsdictionary alloc] init];
Nsstring * STR = [dict objectforkey: @ "key"];
Nslog (@ "% d", [STR intvalue]);

There is an empty dictionary, and then the corresponding value of a non-existent key is obtained from it, received with a string, and converted to the int type with intvalue. The final value obtained is

After getting depressed for a while, I found that returns 0 if the specified ER doesn't begin with a valid decimal text representation of a number.

Suddenly, it means that if the receiver of the message (the STR In the OC) does not start with a valid decimal symbol, 0 is returned.

Bugs discovered and corrected before they can grow

Precautions for intvalue in oC