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James Head
18,872 PointsUse of parseInt()
In the code on this video we use parseInt every time we test a condition. I remember Dave saying we shouldn't repeat code if it is not necessary. Would it not make more sense to convert the string to a number at the time the user inputs it? So.. use parseInt(prompt('Enter your number'));
James Barnett
39,199 PointsDave McFarland - What are your thoughts
4 Answers
Dave McFarland
Treehouse TeacherHi James Head,
You've got a very good point and Darren Healy is correct about why I used parseInt() so many times. Your solution -- parseInt(prompt('Enter your number')) -- is very good, but I didn't use that because that solution involves a lot of mental steps for someone new to the language who might be confused to see so many JavaScript methods combined in a single statement like that.
While "don't repeat yourself" is very good programming, "do repeat yourself" is a good way to learn!
I'm glad you could put the course ideas to good use and figured out a BETTER way to write the code!
@james barnett's solution is also good: store the result of the parseInt() method in a variable and use that variable instead of repeating the use of the parseInt() method.
James Barnett
39,199 PointsPersonally I think this is more readable / maintainable
var rawNum = prompt('Enter your number');
var num = parseInt(rawNum);
than this
var num = parseInt(prompt('Enter your number'));
James Head
18,872 PointsThanks James, I agree this looks much more readable.
wuworkshop
3,429 PointsDon't forget the radix parameter.
var num = parseInt(rawNum, 10);
Per MDN doc - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseInt:
radix
An integer between 2 and 36 that represents the radix (the base in mathematical numeral systems) of the above >mentioned string. Specify 10 for the decimal numeral system commonly used by humans. Always specify this parameter to eliminate reader confusion and to guarantee predictable behavior. Different implementations produce different results when a radix is not specified.
James Head
18,872 PointsThanks everyone for your replies.
Darren Healy
Front End Web Development Techdegree Student 23,565 PointsDarren Healy
Front End Web Development Techdegree Student 23,565 PointsHi James,
While D.R.Y. is something we should all stick to, I think it is just there as clarification for beginners. I wouldn't read into it too much.
Darren