Is it Safe to Check for Non-Null Pointers with `if(pointer)`?

Is It Safe to Check Non-Null Pointers with if(pointer)?

When working with pointers, checking if they are not pointing to NULL is crucial. In C , this has traditionally been done using the comparison operator: if(pointer != NULL). However, a concise alternative has emerged: if(pointer).

Query: Is it safe to использовать if(pointer) instead of if(pointer != NULL)?

Response: Indeed, it is safe and often preferred to use if(pointer) for non-NULL pointer checks.

The C standard defines implicit conversions for boolean expressions. In this case, the null pointer value is automatically converted to false, while non-null pointers are converted to true. This is specified in the C 11 standard, section on Boolean Conversions:

"A prvalue of arithmetic, unscoped enumeration, pointer, or pointer to member type can be converted to a prvalue of type bool. A zero value, null pointer value, or null member pointer value is converted to false; any other value is converted to true. A prvalue of type std::nullptr_t can be converted to a prvalue of type bool; the resulting value is false."

By leveraging this implicit conversion, if(pointer) effectively checks if the pointer is not NULL. This concise syntax enhances readability and reduces verbosity in code.

The above is the detailed content of Is it Safe to Check for Non-Null Pointers with `if(pointer)`?. For more information, please follow other related articles on the PHP Chinese website!