字符串去掉特殊字符和比較字符串大小

 //    截取特殊字符

 NSMutableString*selectDateTextFieldString=[NSMutableString stringWithString: closingDateTextField.text];

    NSRange selectTimeRange = [selectDateTextFieldString rangeOfString:@"-"];

    while (selectTimeRange.location != NSNotFound) {

        selectTimeRange = [selectDateTextFieldString rangeOfString:@"-"];

        if (selectTimeRange.location != NSNotFound) {

            [selectDateTextFieldString deleteCharactersInRange:selectTimeRange];

        }

    }

    

//比較字符串大小

     NSComparisonResult   result  =[presentTimemutableString compare:selectDateTextFieldString];

    

    if (result==NSOrderedDescending) {

}