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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.
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