OC -- 小练习

Posted 2020-06-09

 // 求字符串"158"和"39"按十进制数值做差后的结果以字符串形式输出
        NSString *str1 = @"158";
        NSString *str2 = @"39";
        int a = [str1 intValue];
        int b = [str2 intValue];
        int c = a - b;
        NSString *res = [NSString stringWithFormat:@"%d", c];
        NSLog(@"%@", res);
    
    // 取出字符串"123-456-789-000"中数字部分，组成一个新的字符串输出
        NSString *string = @"123-456-789-000";
        NSArray *array = [string componentsSeparatedByString:@"-"];
        NSString *result = [array componentsJoinedByString:@""];
        NSLog(@"%@", result);
    
    // 有一个数组 @[@"kick", @"off", @10] 将数组中@10去掉
        NSArray *arr5 = @[@"kick", @"off", @10];
        NSMutableString *new = [NSMutableString string];
        for (NSString *obj in arr5){
            if (![obj isKindOfClass:[NSNumber class]]){
                [new appendString:obj];
            }
        }
        NSLog(@"%@", new);
        
    // 将2013年05月05日转换为 2013-05-05
        NSString *time = @"2013/05/05";
        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        formatter.dateFormat = @"yyyy-MM-dd";
        NSDate *date = [formatter dateFromString:time];
        NSLog(@"%@", date);