Hudson Kim2,486 Points
What is the parse int function and what does it do?
SO what exactly does the parse int do? I looked it up but all the explanation seem to be confusing me even more. Please help me understand. Thanks.
Antti Lylander9,641 Points
It converts a string to a number. It only searches the number in the beginning of the string though. If the first character is not a number, NaN is returned.
You can try different values in the console.
parseInt('15 miles') //returs 15 parseInt('about 15 miles') //returns NaN input = prompt('give an integer') //try giving it an integer, it will return "3" if you type in 3. typeof input //try then this in console. it will return "string" integer = parseInt(input) //this will return 3 (no double quotes, meaning that it is a number, not a string anymore) typeof integer //this returns "number" so now you know that your value is stored as a number and you are safe doing some math with it. Many math methods do the conversion automatically, but it is not a good practice to count on it.
I guess you have been using it with prompt(). The reason for that is the fact that prompt always returns a string value even if you type a number in the prompt. Hope this clears it a bit. Trying stuff in console always helps me.