Learning WML, and WMLScript

Arithmetic Operators

WMLScript provides all the normal arithmetic operators. The syntax for these is exactly the same as in C or Java.

The simplest two arithmetic operators are unary plus, represented by +, and unary minus, represented by - . Unary plus simply converts the value to a number,^[12] and unary minus converts the value to a number, then negates it (subtracts it from zero).

For example:

+2 is integer 2

-2 is integer -2

-"-2" is integer 2

-"2e0" is integer -2.0

After the unary operators, there are six binary arithmetic operators. Addition is represented by +, subtraction by - , and multiplication by * . There are two division operators: / , which operates on floating-point numbers and gives a floating-point result, and div , which operates on integers and gives an integer result. The final operator is the modulo or remainder operator, which gives the remainder after integer division and is represented by % .

All of these, other than div, should be familiar to you if you know C or Java. (C and Java use the datatypes of the operands and the result to determine whether to perform integer or floating-point division, so there’s no need for the div operator.)

There’s one slight complication to these operators: as mentioned in Operand Conversions earlier in this chapter, the + operator performs string concatenation rather than addition if either of its operands is a string. This can introduce subtle problems.

Examples:

3 * 2 gives integer 6

"3" * 2 gives integer 6

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