JavaScript and Ajax for the Web: Visual QuickStart Guide, Seventh Edition

Operators

Operators are the symbols used to work with variables. You’re already familiar with operators from simple arithmetic; plus and minus are operators. See Table 1.3 for the full list of operators.

Table 1.3. Operators

Operator	What it does
x + y (Numeric)	Adds x and y together
x + y (String)	Concatenates x and y together
x - y	Subtracts y from x
x * y	Multiplies x and y together
x / y	Divides x by y
x % y	Modulus of x and y (i.e., the remainder when x is divided by y)
x++, ++x	Adds one to x (same as x = x + 1)
x--, --x	Subtracts one from x (same as x = x - 1)
-x	Reverses the sign on x

✓ Tips

• While both x++ and ++x add one to x, they are not identical; the former increments x after the assignment is complete, and the latter before. For example, if x is 5, ...