Expression Operators Reference

The expression language supports operators to enable you to create more complex expressions.

Arithmetic Operators

Expressions based on arithmetic operators result in numerical values.

Operator	Usage	Description
`+`	`1 + 1`	Add two numbers.
`-`	`2 - 1`	Subtract one number from the other.
`*`	`2 * 2`	Multiply two numbers.
`/`	`4 / 2`	Divide one number by the other.
`%`	`5 % 2`	Return the integer remainder of dividing the first number by the second.
`-`	`-v.exp`	Unary operator. Reverses the sign of the succeeding number. For example if the value of `expenses` is `100`, then `-expenses` is `-100`.

Numeric Literals

Literal	Usage	Description
Integer	`2`	Integers are numbers without a decimal point or exponent.
Float	3.14``-1.1e10	Numbers with a decimal point, or numbers with an exponent.
Null	`null`	A literal null number. Matches the explicit null value and numbers with an undefined value.

String Operators

Expressions based on string operators result in string values.

Operator	Usage	Description
`+`	`'Title: ' + v.note.title`	Concatenates two strings together.

String Literals

String literals must be enclosed in single quotation marks 'like this'.

Literal	Usage	Description
string	`'hello world'`	Literal strings must be enclosed in single quotation marks. Double quotation marks are reserved for enclosing attribute values, and must be escaped in strings.
\<escape>	`'\n'`	Whitespace characters: `\t` (tab), `\n` (newline), or `\r` (carriage return). Escaped characters: `\"` (literal ”), `\'` (literal ’), or `\\` (literal \).
Unicode	`'\u####'`	A Unicode code point. The # symbols are hexadecimal digits. A Unicode literal requires four digits.
null	`null`	A literal null string. Matches the explicit null value and strings with an undefined value.

Comparison Operators

Expressions based on comparison operators result in a true or false value. For comparison purposes, numbers are treated as the same type. In all other cases, comparisons check both value and type.

Operator	Alternative	Usage	Description
`==`	`eq`	`1 == 1` `1 == 1.0` `1 eq 1`	Returns `true` if the operands are equal. This comparison is valid for all data types.
`!=`	`ne`	1 != 2``1 != true``1 != '1'``null != false``1 ne 2	Returns `true` if the operands are not equal. This comparison is valid for all data types.
`<`	`lt`	1 < 2``1 lt 2	Returns `true` if the first operand is numerically less than the second. You must escape the `<` operator to `<` to use it in component markup. Alternatively, you can use the `lt` operator.
`>`	`gt`	42 > 2``42 gt 2	Returns `true` if the first operand is numerically greater than the second.
`<=`	`le`	2 <= 42``2 le 42	Returns `true` if the first operand is numerically less than or equal to the second. You must escape the `<=` operator to `<=` to use it in component markup. Alternatively, you can use the `le` operator.
`>=`	`ge`	42 >= 42``42 ge 42	Returns `true` if the first operand is numerically greater than or equal to the second.

undefined==null evaluates to true.

Don’t use the == operator for objects, as opposed to basic types, such as Integer or String. For example, object1==object2 evaluates inconsistently on the client versus the server and isn’t reliable.

Warning

Logical Operators

Expressions based on logical operators result in a true or false value.

Operator	Usage	Description
`&&`	`isEnabled && hasPermission`	Returns `true` if both operands are individually true. If you have more than two arguments, you can chain multiple `&&` operations. This syntax is awkward in markup so we recommend the alternative of using the `and()` function when you have two arguments. For example, `and(isEnabled, hasPermission)`. The `and()` function only works with two arguments.
`\|\|`	`hasPermission \|\| isRequired`	Returns `true` if either operand is individually true. If you have more than two arguments, you can chain multiple `\|\|` operations. You can alternatively use the `or()` function when you have only two arguments. The `or()` function only works with two arguments.
`!`	`!isRequired`	Unary operator. Returns `true` if the operand is false. This operator should not be confused with the `!` delimiter used to start an expression in `{!`. You can combine the expression delimiter with this negation operator to return the logical negation of a value, for example, `{!!true}` returns `false`.

Logical Literals

Logical values are never equivalent to non-logical values. That is, only true == true, and only false == false; 1 != true, and 0 != false, and null != false.

Literal	Usage	Description
true	`true`	A boolean `true` value.
false	`false`	A boolean `false` value.

Conditional Operator

There is only one conditional operator, the traditional ternary operator.

Operator	Usage	Description
`? :`	`(1 != 2) ? "Obviously" : "Black is White"`	The operand before the `?` operator is evaluated as a boolean. If true, the second operand is returned. If false, the third operand is returned.

See Also

Expression Functions Reference