IOS 字面量语法

字面量语法：

NSNumber* intNum =@5;

NSNumber* floatNum =@1.4f;

NSNumber* boolNum =@YES;

NSArray* array =@[@"dog",@"cat"];

NSString* dog = array[0];

id object1 = /* … */;

id object2 = /* … */;

id object3 = /* … */;

NSArray * arrayA = [NSArray arrayWithObjects:object1,object2,object3,nil];

NSArray * arrayB = @[object1,object2,object3];

字面量语法创建字典，键在值得前面

NSDictionary* dic =@{@"firstName":@"王",@"lastName":@"小哥"};

NSString * lastName = dic[@“lastName”];