# Variables, Data Types, and Mathematical Operators

Use this article as a reference sheet for JavaScript variables, data types, and mathematical operators.

Use this article as a reference sheet for JavaScript variables, data types, and mathematical operators.

• Variables — The `var` keyword indicates the creation of a variable.
• Data Types — `'New York City'` is a string, `40.7` is a number, and `true` is a boolean.
• Mathematical Operators — The addition (`+`), subtraction (`-`), multiplication (`*`), and division (`/`) characters function as mathematical operators.
`var location = 'New York City';var latitude = 40.7;var inNorthernHemisphere = true;`

Each line in the example above begins with the keyword `var`. The `var` keyword is used to create a variable. The word that immediately follows `var` is the name of the variable. The variable’s name should describe the value that it stores (e.g. `location`).

Variables can store any data type, including:

• String — Any grouping of keyboard characters (letters, spaces, numbers, or symbols) surrounded by single quotes (`'Hello'`) or double quotes (`"World!"`). In the example above, the string `'New York City'` is saved to the variable `location`.
• Number — Any number, including numbers with decimals: `4`, `1516`, `.002`, `23.42`. In the example above, the number `40.7` is saved to the variable `latitude`.
• Boolean — Either `true` or `false`, with no quotations. In the example above, the variable `inNorthernHemisphere` is set to `true`. The sample code below contains examples of mathematical expressions:
`var num1 = 4;var num2 = 9;var addNumbers = num1 + num2; // addNumbers equals 13var subtractNumbers = num2 - num1; // subtractNumbers equals 5var multiplyNumbers = num1 * num2; // multiplyNumbers equals 36var divideNumbers = num2 / num1; // divideNumbers equals 2.25`

In the example above, the values saved to the variables were calculated using the addition (`+`), subtraction (`-`), multiplication (`*`), and division (`/`) operators.

Variables always store the final value of the expression on the right side of the equals sign (`=`).