EL expressions provide the following operators: (The information is from JSP Tutorial)

Type Operators Description
Arithmetic +, - (binary), *, /, div, %, mod, - (unary) - / and div are the same, while % and mod are the same.
Logical and, &&, or, ||, not, !, empty  
Relational ==, eq, !=, ne, <, lt, >, gt, <=, ge, >=, le - Comparisons can be made against other values, or against boolean, string, integer, or floating point literals.
Conditional A ? B : C It evaluate B or C, depending on the result of the evaluation of A.
Index [] To evaluate expr-a[expr-b], evaluate expr-a into value-a and evaluate expr-b into value-b. If either value-a or value-b is null, return null.

- If value-a is a Map, return value-a.get(value-b). If !value-a.containsKey(value-b), then return null.
- If value-a is a List or array, coerce value-b to int and return value-a.get(value-b) or Array.get(value-a, value-b), as appropriate. If the coercion couldn’t be performed, an error is returned. If the get call returns an IndexOutOfBoundsException, null is returned. If the get call returns another exception, an error is returned.
- If value-a is a JavaBeans object, coerce value-b to String. If value-b is a readable property of value-a, then return the result of a get call. If the get method throws an exception, an error is returned.
Member . - Properties of variables are accessed using the . operator and can be nested arbitrarily.
- The value of a map can be accessed by using the . operator.
Assignment = ssigns a value to a variable.
Semicolon ; Evaluates multiple expressions and returns the result of the last one.

The relative precedence levels of operators, from highest to lowest (left to right), are organized as follows:

Precedence Operators Description
Highest [], . Member and index access
  () Grouping (used to change evaluation order)
  - (unary), not, !, empty Unary operators
  *, /, div, %, mod Multiplicative operators
  +, -, += Additive operators and String concatenation
  <, >, <=, >=, lt, gt, le, ge Relational operators
  ==, !=, eq, ne Equality operators
  &&, and Logical AND
  \|\|, or Logical OR
  ? : Conditional (ternary) operator
  = Assignment operator
Lowest ; Semicolon operator