1.16、建议:BOOL的陷阱,不要直接将BOOL值与YES进行比较

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说明:Ojbective-C中把BOOL定义成无符号字符型,这意味着BOOL类型

的值远不止YES(1)或

NO(0),所以,不要直接将BOOL值与YES进行比较。

示例-1:BOOL a = 2.5;

if (a == YES) {

NSLog(@"a == yes"); }

else if(a == NO){

NSLog(@"a == no"); }

else

{NSLog(@"a == other");

}NSLog(@"a+0.5 = %f",a+0.5);iOS编程规范v1.0

==========2014-04-07 21:56:14.280 2014-04-07 21:56:14.281示例-2:BOOL a =130;

if (a == YES) {

NSLog(@"a == yes"); }

else if(a == NO){

NSLog(@"a == no"); }

else

{NSLog(@"a == other");

test[1224:907] a == other test[1224:907] a+0.5 = 2.500000

}NSLog(@"a=%hhd a+0.5 = %f",a,a+0.5);==========2014-04-07 22:14:07.986

test[1510:907] a == other2014-04-07 22:14:07.988 test[1510:907] a=-126 a+0.5 =

-125.500000