调用方法

[object  method];
[object methodWithInput:input];

output = [object methodWithOutput];
output = [object methodWithInputAndOutput:input];

id myObject = [NSString string];
NSString* myString = [NSString string];

嵌套消息

function1 ( function2() );
[NSString stringWithFormat:[prefs format]];

多个输入参数的方法

-(BOOL)writeToFile:(NSString *)path atomically:(BOOL)useAuxiliaryFile;
BOOL result = [myData writeToFile:@"/tmp/log.txt"atomically:NO];

原文：learn_objective_C part 1