Differences between BOOL and bool in OC language: ocbool

Differences between BOOL and bool in OC language: ocbool

1. Different Types

BOOL is int type;

Bool is boolean;

 

2. Different Lengths

Bool has only one byte;

The BOOL length depends on the actual environment. Generally, it can be regarded as 4 bytes;

3. Different values

Bool values: false and true, which are the difference between 0 and 1;

BOOL values: FALSE and TRUE, which are the difference between 0 and non-0;

The following is an example.

# Import <Foundation/Foundation. h>

 

Int main (int argc, const char * argv []) {

@ Autoreleasepool {

BOOL b1 = 3;

Bool b2 = 3;

BOOL b3= 256;

Bool b4 = 256;

NSLog (@ "b1 = % d", b1 );

NSLog (@ "b2 = % d", b2 );

NSLog (@ "b3 = % d", b3 );

NSLog (@ "b4 = % d", b4 );

}

Return 0;

}

The output is as follows:

Because b2 is of the bool type, b2 can only be 1 or 0; that is, b2 = b4 = 1.

Because b3 is of the BOOL type and has 8-bit storage space, the value range of b3 is-256 ~ 255.

Because 256 is converted to hexadecimal = 0X100, b3 = 0; b1 = 3.

Finally, we can conclude that if the variable is of the BOOL type, as long as the value is greater than 255, the result can only be a low 8-bit value;

If b3 = 272, the print result is b3 = 16.