iOS 判断一断代码的执行时间（从网上看的，自己实现一下）

//创建一个.h 文件

// Method.h

#ifndef NonAtomicTest_Method_h

#define NonAtomicTest_Method_h

#import <mach/mach_time.h>  

//c函数实现  返回值类型 函数名  函数参数（是一个block）

CGFloat BNRTimeBlock (void (^block)(void)) {

    mach_timebase_info_data_t info;

    if (mach_timebase_info(&info) != KERN_SUCCESS) return -1.0;

    

    uint64_t start = mach_absolute_time ();

    block ();

    uint64_t end = mach_absolute_time ();

    uint64_t elapsed = end - start;

    

    uint64_t nanos = elapsed * info.numer / info.denom;

    return (CGFloat)nanos / NSEC_PER_SEC;

    

} // BNRTimeBlock

#endif

 

//直接使用

#import "ViewController.h"

#import "Method.h"           //引用头文件即可调用 BNRTimeBlock

#define LOOPAGE 10000000

@interface ViewController ()

@end

 

@implementation ViewController

 

- (void)viewDidLoad {

    [super viewDidLoad];

    [self test];

    

}

 

-(void)test {

    CGFloat time;

 

    NSString *thing1 = @"hi";

    NSString *thing2 = @"hello there";

 

  //block 的实现

    time = BNRTimeBlock(^{

        for (int i = 0; i < LOOPAGE; i++) {

            [thing1 isEqual: thing2];

        }

    });

    

    NSLog (@"isEqual: time: %f ", time);

    

    time = BNRTimeBlock(^{

        for (int i = 0; i < LOOPAGE; i++) {

            [thing1 isEqualToString: thing2];

        }

    });

    NSLog(@"isEqualToString: time: %f ", time);

    

}

@end

控制台输出：

NonAtomicTest[3114:126739] isEqual: time: 0.279763

NonAtomicTest[3114:126739] isEqualToString: time: 0.275132