Documentation Index
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ZEN provides operators for arithmetic, comparison, logic, and data manipulation.
Arithmetic operators
Perform mathematical calculations on numbers.
| Operator | Name | Example | Result |
|---|
+ | Addition | 5 + 3 | 8 |
- | Subtraction | 10 - 4 | 6 |
* | Multiplication | 6 * 7 | 42 |
/ | Division | 15 / 3 | 5 |
% | Modulo (remainder) | 17 % 5 | 2 |
^ | Power | 2 ^ 10 | 1024 |
Operator precedence
Operations follow standard mathematical precedence:
^ (power)*, /, % (multiply, divide, modulo)+, - (add, subtract)
Use parentheses to control order:
(5 + 3) * 2 // 16, not 11
10 / (2 + 3) // 2, not 7
Comparison operators
Compare values and return boolean results.
| Operator | Name | Example | Result |
|---|
== | Equal | 5 == 5 | true |
!= | Not equal | 5 != 3 | true |
> | Greater than | 10 > 5 | true |
< | Less than | 3 < 10 | true |
>= | Greater or equal | 5 >= 5 | true |
<= | Less or equal | 3 <= 5 | true |
Logical operators
Combine boolean conditions.
| Operator | Name | Example | Result |
|---|
and | Logical AND | true and false | false |
or | Logical OR | true or false | true |
not | Logical NOT | not true | false |
Short-circuit evaluation
Logical operators stop early when the result is determined:
false and expensiveFunction() // Never calls the function
true or expensiveFunction() // Never calls the function
Ternary operator
Conditionally return one of two values.
condition ? valueIfTrue : valueIfFalse
age >= 18 ? "adult" : "minor"
score >= 70 ? "pass" : "fail"
stock > 0 ? "In Stock" : "Out of Stock"
score >= 90 ? "A" : score >= 80 ? "B" : score >= 70 ? "C" : "F"
Null coalescing operator
Return the first non-null value.
Examples:
user.nickname ?? user.name // Use nickname, fall back to name
config.timeout ?? 30 // Use config or default to 30
a ?? b ?? c ?? "default" // Chain multiple fallbacks
Membership operators
Check if a value exists in a collection or range.
In operator
// Array membership
"US" in ["US", "CA", "GB"] // true
5 in [1, 2, 3, 4, 5] // true
// Range membership (inclusive)
x in [1..10] // true if 1 <= x <= 10
// Range membership (exclusive)
x in (0..100) // true if 0 < x < 100
// Mixed brackets
x in [0..100) // true if 0 <= x < 100
x in (0..100] // true if 0 < x <= 100
Not in operator
Negate membership tests:
status not in ["deleted", "archived"]
x not in [0..100]
String operators
Concatenation
The + operator joins strings:
"Hello" + " " + "World" // "Hello World"
"Order #" + string(orderId) // "Order #12345"
firstName + " " + lastName // "John Doe"
Template strings
Embed expressions in strings:
`Hello, ${name}!`
`Total: ${round(total, 2)}`
`Items: ${len(items)}`
Array operators
Index access
items[0] // First item
items[len(items) - 1] // Last item
items[-1] // Last item (negative index)
Object operators
Property access
user.name // Dot notation
user["name"] // Bracket notation
user[fieldName] // Dynamic key
Optional chaining
Access nested properties is optional:
user.address.city // Returns null if any part is null
Operator precedence table
From highest to lowest precedence:
| Precedence | Operators |
|---|
| 1 | () (grouping) |
| 2 | ., [] (property access) |
| 3 | +, - (unary) |
| 4 | ?? (null coalescing) |
| 5 | ^ (power, right-associative) |
| 6 | *, /, % |
| 7 | not (unary) |
| 8 | +, - (binary) |
| 9 | ==, !=, <, >, <=, >=, in, not in |
| 10 | and |
| 11 | or |
| 12 | ? : (ternary) |
