Objective-C中3种枚举比较及KVC两个小技巧

时间：2014-03-19 12:06:26 阅读：295 评论：0 收藏：0 [点我收藏+]

Objective-C中3种枚举比较及KVO两个小技巧

一：oc的3种枚举

for循环
for in
枚举块

如代码

NSUInteger 
totalCount = 10000;
NSMutableArray 
*array = [NSMutableArray 
arrayWithCapacity:totalCount];
    //create an array including 10000 elements
for (int i = 0; i<totalCount; i++) {
    array[i] = [@(i) stringValue];
}
    //C Language For Loop Enumeration
CFTimeInterval start1 = CACurrentMediaTime();
for (int j = 0; j< totalCount; j++) {
    NSLog(@"%@",array[j]);
}
CFTimeInterval end1 = CACurrentMediaTime();
NSLog(@"C Language For Loop method %f",end1 - start1);
    //Objective-C Fast Enumeration
CFTimeInterval start2 = CACurrentMediaTime();
for (NSString 
*string in array) {
    NSLog(@"%@",string);
}
CFTimeInterval end2 = CACurrentMediaTime();
NSLog(@"Objective-C Fast Enumeration method %f",end2 - start2);
    //Objective-C Block Enumeration
CFTimeInterval start3 = CACurrentMediaTime();
[array enumerateObjectsWithOptions:NSEnumerationConcurrent 
usingBlock:^(NSString 
* obj, NSUInteger 
idx, BOOL 
*stop) {
    NSLog(@"%@",obj);
}];
CFTimeInterval end3 = CACurrentMediaTime();
NSLog(@"Objective-C Block Enumeration method %f",end3 - start3);