OC自动释放池在for循环中的性能测试

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    
    NSLog(@"start");
    
    CFAbsoluteTime start = CFAbsoluteTimeGetCurrent();
    [self test1];
    NSLog(@"外 %f", CFAbsoluteTimeGetCurrent() - start);
    
    start = CFAbsoluteTimeGetCurrent();
    [self test2];
    NSLog(@"内 %f", CFAbsoluteTimeGetCurrent() - start);
    
    NSLog(@"over");
}

- (void)test2 {
    for (long i = 0; i < largeNumber; ++i) {
        @autoreleasepool {
            NSString *str = [NSString stringWithFormat:@"hello - %ld", i];
            str = [str uppercaseString];
            str = [str stringByAppendingString:@" - world"];
        }
    }
}

- (void)test1 {
    @autoreleasepool {
        for (long i = 0; i < largeNumber; ++i) {
            NSString *str = [NSString stringWithFormat:@"hello - %ld", i];
            str = [str uppercaseString];
            str = [str stringByAppendingString:@" - world"];
        }
    }
}