In addition to console
, there are other objects built into JavaScript.
Down the line, you’ll build your own objects, but for now these “built-in” objects are full of useful functionality.
For example, if you wanted to perform more complex mathematical operations than arithmetic, JavaScript has the built-in Math
object.
The great thing about objects is that they have methods! Let’s call the .random()
method from the built-in Math
object:
console.log(Math.random()); // Prints a random number between 0 and 1
In the example above, we called the .random()
method by appending the object name with the dot operator, the name of the method, and opening and closing parentheses. This method returns a random number between 0 (inclusive) and 1 (exclusive).
To generate a random number between 0 and 50, we could multiply this result by 50, like so:
Math.random() * 50;
The example above will likely evaluate to a decimal. To ensure the answer is a whole number, we can take advantage of another useful Math
method called Math.floor()
.
Math.floor()
takes a decimal number, and rounds down to the nearest whole number. You can use Math.floor()
to round down a random number like this:
Math.floor(Math.random() * 50);
In this case:
Math.random()
generates a random number between 0 and 1.- We then multiply that number by
50
, so now we have a number between 0 and 50. - Then,
Math.floor()
rounds the number down to the nearest whole number.
If you wanted to see the number printed to the terminal, you would still need to use a console.log()
statement:
console.log(Math.floor(Math.random() * 50)); // Prints a random whole number between 0 and 50
To see all of the properties and methods on the Math
object, take a look at the documentation here.
Instructions
Inside of a console.log()
, create a random number with Math.random()
, then multiply it by 100
.
Now, use Math.floor()
to make the output a whole number.
Inside the console.log()
you wrote in the last step, put the existing Math.random() * 100
code inside the parentheses of Math.floor()
.
Find a method on the JavaScript Math
object that returns the smallest integer greater than or equal to a decimal number.
Use this method with the number 43.8
. Log the answer to the console.
Use the JavaScript documentation to find a method on the built-in Number
object that checks if a number is an integer.
Put the number 2017
in the parentheses of the method and use console.log()
to print the result.