Operators

Mathematical

Name	Syntax example	Comments
Multiplication	`a * b`
Division	`a / b`
Remainder	`a % b`	Often called mod or modulus
Addition	`a + b`
Subtraction	`a - b`
Exponent	`a ** b`	Do not confuse this with Bitwise Xor ^
Bitshift Right	`a >> b`
Bitshift Left	`a << b`
Bitwise And	`a & b`
Bitwise Or	`a \| b`
Bitwise Xor	`a ^ b`

The mathematical operators can also be used in the syntax a <operator>= b, for example, a += b.

This is merely a shortcut for a = a <operator> b, or in our example a = a + b.

Relational and Logical

Name	Syntax Example	Comments
Less Than	`a < b`
Greater Than	`a > b`
Less Than or Equal To	`a <= b`
Greater Than or Equal To	`a >= b`
Equality	`a == b`
Inequality	`a != b`
Logical And	`a and b`	Only use when `a` and `b` are boolean values
Logical Or	`a or b`	Only use when `a` and `b` are boolean values
Logical Not	`not a`	Only use when `a` is a boolean value

Types

Name	Syntax Example	Comments
Typecast	`a cast string`
Typecast	`a as string`
Type Equality/Compatibility	`a isa string`
Type Retrieval	`typeof(string)`
Type Retrieval	`a.GetType()`

Primary

Name	Syntax Example	Comments
Member	`A.B`	Classes are described in Part 08 - Classes
Function Call	`f(x)`	Functions are described in Part 07 - Functions
Post Increment	`i++`	See Difference between Pre and Post Increment/Decrement
Post Decrement	`i--`	See Difference between Pre and Post Increment/Decrement
Constructor Call	`o = MyClass()`	Classes are described in Part 08 - Classes

Unary

Name	Syntax Example	Comments
Negative Value	`-5`
Pre Increment	`++i`	See [Difference between Pre and Post Increment/Decrement](https://github.com/bamboo/boo/wiki/Boo-Primer:-%5BPart-06%5D-Operators)
Pre Decrement	`--i`	See [Difference between Pre and Post Increment/Decrement](https://github.com/bamboo/boo/wiki/Boo-Primer:-%5BPart-06%5D-Operators)
Grouping	`(a + b)`

Difference between Pre and Post Increment/Decrement

When writing inline code, Pre Increment/Decrement (+i/-i) commit the action, then return its new value, whereas Post Increment/Decrement (i+/i-) return the current value, then commit the change.

preincrement vs. postincrement

num = 0
for i in range(5):
    print num++
print '---'
num = 0
for i in range(5):
    print ++num

// Output:
// 0
// 1
// 2
// 3
// 4
// ---
// 1
// 2
// 3
// 4
// 5

Hint

To make your code more readable, avoid using the incrementors and decrementors. Instead, use i += 1 and i -= 1.

Exercises

Put your hands on a wall, move your left foot back about 3 feet, move the right foot back 2 feet.