Changes

In [[Introducing JavaScript Variables]] we looked at the '=' assigmnent assignent operator. This is the most basic of assigmnet assignment operators and serves to simply assign a value to a variable. For example y = 10 assigns the value of 10 to a variable called y.

The '=' assignment operator does not make any changes to the value before it is assigned to the variable. A number of assigment assignment operators are available, however, that perform arithmetic on the value before assigning it to the variable. These are essentially combined arithmetic and assigment assignment operators. The most common operators of this type, and their "long hand" equivalents are shown below:

These combined operators essentially provide a short way of assigning the results of arithmetic expressesions expressions between two variables or a variable and a value and having the result assigned to the first variable.For example: <pre>var x = 10;x += 5; // Assigns a value of 15 to variable x (the same as x = x + 5) var y = 20;y -= 10; // Assigns a value of 10 to variable y (the same as y = y - 10) var x = 10;var y = 5; x /= y; // Assigns a value of 2 to variable x (the same as x = x / y) </pre> <pre>