Operators
The following chart is a complete list and description of all operators present in MVEL.
Unary Operators
| Operator |
Description |
Example |
| new |
Object instantiation |
new String("foo") |
| with |
Block WITH Operator. Perform multiple operations on a single object instance |
with (value) { name = 'Foo', age = 18, sex = Sex.FEMALE } |
| assert |
Assert that a value is true or fail with an AssertionError |
assert foo != null |
Comparison Operators
| Operator |
Description |
Example |
| == |
Equality Check. Checks to see if the values on both sides of the operator are equal. Unlike Java, this is not an identity check.
|
"foo" == "foo" is true
|
| != |
Not Equals Check. Checks to see if the values on both sides of the operator are not equal.
|
"foo" == "bar" is false
|
| > |
Greater Than Check. Checks to see if the value on the left side of the operator is greater than than value on the right.
|
2 > 1 is true
|
| < |
Less Than Check. Checks to see if the value on the left side of the operator is less than value on the right.
|
1 < 2 is true
|
>=
|
Greater Than or Equal. Checks to see if the value on the left hand side is greater than or equal to the value on the right.
|
1 >= 1 is true
|
| <= |
Less Than or Equal. Checks to see if the value on the left hand side is less than or equal to the value on the right.
|
2 <= 2 is true
|
| contains |
Value Containment Check. Checks to see if the value on the left contains the value on the right. For more details on how this operator works, see [Contains Operator]
|
var contains "Foo"
|
is or instanceof
|
Type Checking Operator. Checks to see if the value on the left is a member of the class on the right.
|
var instanceof Integer
|
| strsim |
String Similarity Check. Compares to strings and returns a similarity between them as a percentage. See: String Similarity Check.
|
"foobie" strsim "foobar"
|
| soundslike |
Soundex Check. Performs a soundex comparison between two strings. See: [Soundex].
|
"foobar" soundslike "fubar"
|
Logical Operators
| Operator |
Description
|
Example
|
| && |
Logical AND. Checks to see that the values on both sides of the operator are true.
|
foo && bar
|
| || |
Logical OR. Checks to see if either the value on the left or the right is true.
|
foo || bar
|
or
|
Chained OR. Checks a sequence of values for emptiness and returns the first non-empty value.
|
foo or bar or barfoo or 'N/A'
|
| ~= |
Regular Expression Match. Checks to see if the value on the left matches the regular expression on the right.
|
foo ~= '[a-z].+' |
Bitwise Operators
| Operator |
Description
|
Example
|
| & |
Bitwise AND.
|
foo & 5 |
| | |
Bitwise OR.
|
foo | 5 |
| ^ |
Bitwise XOR.
|
foo ^ 5 |
Arithmetic Operators
| Operator |
Description
|
Example
|
+
|
Addition. Adds the value on the left to the value on the right
|
1 + 2
|
| - |
Subtraction. Subtracts the value on the right from the value on the left
|
2 - 1
|
| / |
Division. Divides the number on the left by the number on the right
|
2 / 1
|
*
|
Multiplication. Multiples the number on the left by the number on the right
|
1 * 2
|
%
|
Modulus. Divides the number on the left by the number on the right and returns the remainder.
|
2 % 1
|
Other Operators
| Operator |
Description
|
Example
|
| + |
String Concatenation. Overloaded operator for concatenating two strings together.
|
"foo" + ;bar"
|
| # |
Concatenation Operator. Concatenates two literals as strings.
|
1 # 2 returns "12"
|
| in |
Projection/Fold. Projects across a collection. See: Projections and Folds.
|
(foo in list)
|
=
|
Assignment. Assigns the value on the right to the variable on the left.
|
var = "foobar"
|
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