public/subjects/wololo

🌟 Wololo 🧙

Converting types

As you now know, the number 42 is different than the string '42', but if we write `${42}` we converted the number to a string !

We see it because of the delimiters, but it is also true for the memory in your computer.

For example we can not multiply strings, if you try to do 'hello' * 2 or 'hello' * 'hello' you will have an unexpected result.

Well what were you expecting really ? 'hellohello' maybe ?

So sometimes it is useful to go from strings to number to boolean and back !

• Number is a function to convert to a number.
• Boolean is a function to convert to a boolean.
• String is a function to convert to, you guessed it, a string.

So to convert a boolean to a string we would write:

String(true)

One other way we can use placeholders for, is to convert from any values to a string, but using functions is clearer than abusing placeholder syntax:

let str42Placeholder = `${42}` // was this a mistake ?
let str42Function = String(42) // ah okay we want a string !

So there you have it, calling, arguments and return values. Let's see you apply all of that now.

Instructions

For this exercise, we provided 3 variables num, bool and str of a matching type.

Using the magical power of functions, execute the following conversions:

• Declare a stringFromNumber variable of the converted value of num to a string
• Declare a stringFromBoolean variable of the converted value of bool to a string
• Declare a numberFromString variable of the converted value of str to a number
• Declare a numberFromBoolean variable of the converted value of bool to a number
• Declare a booleanFromString variable of the converted value of str to a boolean
• Declare a booleanFromNumber variable of the converted value of num to a boolean