iOS实用小工具

    CFTimeInterval begin = CFAbsoluteTimeGetCurrent();
    for (NSInteger i = 0; i< 5000; i++) {
        NSLog(@"123456");
    }
    CFTimeInterval end = CFAbsoluteTimeGetCurrent();

    NSDate *begin = [NSDate date];
    for (NSInteger i = 0; i< 5000; i++) {
        NSLog(@"123456");
    }
    NSDate *end = [NSDate date];
    
    NSLog(@"%f",[end timeIntervalSinceDate:begin]);

NSTimeInterval start = [[NSDate date] timeIntervalSince1970]*1;
    for (NSInteger i = 0; i< 5000; i++) {
        NSLog(@"------%ld",i);
    }
    NSTimeInterval end = [[NSDate date] timeIntervalSince1970]*1;
    NSTimeInterval value = end - start;
    int second = (int)value %60;//秒
    int minute = (int)value /60%60;
    int house = (int)value / (24 * 3600)%3600;
    int day = (int)value / (24 * 3600);
    NSString *str;
    if (day != 0) {
        str = [NSString stringWithFormat:@"耗时%d天%d小时%d分%d秒",day,house,minute,second];
    }else if (day==0 && house != 0) {
        str = [NSString stringWithFormat:@"耗时%d小时%d分%d秒",house,minute,second];
    }else if (day== 0 && house== 0 && minute!=0) {
        str = [NSString stringWithFormat:@"耗时%d分%d秒",minute,second];
    }else{
        str = [NSString stringWithFormat:@"耗时%d秒",second];
    }
    return str;