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10,338 Pointshow to parseInt and parseFloat on one number?
This is from the teaching video at 3:57 minutes in...
Just to check that my code is right?
I have a number 202.99
I want to use parseInt and parseFloat
let number = (parseInt, parseFloat("202.99"));
// Output below
number = 202.99
typeof number = "number"
I sure that the parseInt worked to convert to a number, I think parseFloat works to include .99 is my code ok?
2 Answers
jb30
44,806 PointsYour code works, but you can simplify your code to let number = parseFloat("202.99");
.
Both parseInt()
and parseFloat()
can convert strings to numbers. To convert "202.99" to an integer, you could use number = parseInt("202.99");
, and the value for number
would be 202
. To convert "202.99" to a float, you could use number = parseFloat("202.99")
, and the value for number
would be 202.99
.
In the code let number = (parseInt, parseFloat("202.99"));
, JavaScript first evaluates the first expression in the parentheses, parseInt
, which has no parentheses, so it refers to the function parseInt()
, and is not printing anything or changing your string. JavaScript next evaluates parseFloat("202.99")
, which evaluates to the number 202.99
, and since it's the last item in the parentheses, its value is assigned to number
.
If you wanted to chain function calls, you could do let number = parseFloat(parseInt("202.99"));
, which first evaluates the inner expression parseInt("202.99")
, which is 202
. JavaScript then evaluates the outer expression with the result of that calculation, and so evaluates parseFloat(202)
, which is 202
, and sets that as the value for number
. You could instead do let number = parseInt(parseFloat("202.99"))
, which simplifies to let number = parseInt(202.99)
, which simplifies to let number = 202;
, which is the same result, the result of let number = parseInt("202.99");
. If you convert a string using the function parseInt()
, you lose everything after the decimal point.
ja5on
10,338 PointsThank you jb30!! I had just progressed onto a challenge and seen this exact thing! I discovered that parseFloat works the same way as parseInt regarding conversion of strings into numbers, something I must have missed...
Thanks for your awesome explanation.
Happy coding..