Math Object¶JavaScript provides several built-in objects, which can be called directly by
the user. One of these is the Math object, which contains more than the
standard mathematical operations (+, -, *, /).
In the previous sections, we learned how to construct, modify, and use objects
such as giraffe. However, JavaScript built-in objects cannot be modified
by the user.
Unlike other objects, theMathobject is immutable.
Math Properties Are Constants¶The Math object has 8 defined properties. These represent mathematical
constants, like the value for pi (π) or the square root of 2.
Instead of defining a variable to hold as many digits of pi as we can remember,
JavaScript stores the value for us. To use this value, we do NOT need to
create a new object. By using dot notation and calling Math.PI, we can
access the value of pi.
Example
1console.log(Math.PI);
2console.log(Math.PI*4);
3console.log(Math.PI + Math.PI);
Console Output
3.141592653589793
12.566370614359172
6.283185307179586
As stated above, the properties within Math cannot be changed by the
user.
Example
1console.log(Math.PI);
2
3Math.PI = 1234;
4
5console.log(Math.PI);
Console Output
3.141592653589793
3.141592653589793
To use one of the other constants stored in Math, we replace PI with
the property name (e.g. SQRT2 stores the value for the square root of 2).
Math Properties¶Besides the value of pi, JavaScript provides 7 other constants. How useful you find each of these depends on the type of project you need to complete.
More powerful uses of the Math object involve using methods, which we
will examine next.