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Juan David Hernandez
7,415 PointsWhy don't we use parsefloat() instead Math.floor()?
So,I have something like:
var question = parsefloat(Math.Radom() * 6 + 1);
alert("I have" + question);
If the code runs inside out when the first parts is done we should have a decimal random number and then parsefloat would does the rest but it doesn't work and I don't know why.
Could you tell me why?
1 Answer
Seth Kroger
56,413 PointsparseFloat() will return the same number that went in since the the decimal point is a valid part of a floating point number. Perhaps you mean parseInt() instead? Two reasons I can think of:
With Math.floor() the function does exactly when you want it to do, drop the digits after the decimal place. parseInt() turns strings into numbers and you're relying on a side-effect to do what you want. Math.floor() makes your intentions clear to anyone reading the code.
parseInt() has a hidden cost. It takes a string argument but you're passing it a number. The number you input will get converted to a string automatically, so it can be converted back to a number. This is much less efficient than Math.floor().
Juan David Hernandez
7,415 Pointsyes, I meant parseint(). Thanks for your time, you're right!
Tony Martin
5,570 PointsTony Martin
5,570 PointsparseFloat() returns a floating point number whereas Math.floor() will return the whole integer rounded down.
The purpose of using Math.floor() is to get back a whole number, not a decimal. In this example, we don't want a decimal, which parseFloat would give us.