???????????????????target
????????VVStack??NSObject????????????????????????????????????????????в???????????????????????????????????????????????????push??????push??????????????????push???????????????????push????????????????????????????д??

 


- (void)testPushANumberAndGetIt {
VVStack *stack = [VVStack new];
[stack push:2.3];
double topNumber = [stack top];
XCTAssertEqual(topNumber?? 2.3?? @"VVStack should can be pushed and has that top value.");
}

 

??????????????????-push:??-top?????????????????????????????ARC??????????????????????????????????????????????VVStack.h???????????????????????.m?????????н???????????????????????????????push?????????????2.3???????

 

//VVStack.h
@interface VVStack : NSObject
- (void)push:(double)num;
- (double)top;
@end
//VVStack.m
@implementation VVStack
- (void)push:(double)num {
}
- (double)top {
return 2.3;
}
@end

 

??????????в?????????????????????????????????????????????????????????????????????????push???4.6???????top???????????????????????????????????????????????????????????????????У???????????????????????????????????????????????????????????????Щerror-try????裬???????????????????????????????????????????????????????????????????????????TDD?????????????????б????????????????????????????????г??????????????п????????????????????????á?????????????·??????????????????????????????????????????VVStackTests.m?У?????????????м????

 

????- (void)testPushANumberAndGetIt {
????//...
????[stack push:4.6];
????topNumber = [stack top];
????XCTAssertEqual(topNumber?? 4.6?? @"Top value of VVStack should be the last num pushed into it");
????}