Add operators precedence documentation

Closes symfony#19803

reference/formats/expression_language.rst

@@ -431,6 +431,51 @@ Other Operators
 * ``?.`` (:ref:`null-safe operator <component-expression-null-safe-operator>`)
 * ``??`` (:ref:`null-coalescing operator <component-expression-null-coalescing-operator>`)
 
+Operators Precedence
+~~~~~~~~~~~~~~~~~~~~
+
+The following table summarize the operators and their precedence. It can be useful to understand the actual behavior of an expression.
+
+To avoid ambiguities it is a good practice to add parentheses.
+
+=============  ==========
+Operator       Precedence
+=============  ==========
+`not`          50
+`!`            50
+`-`            500
+`+`            500
+`or`           10
+`||`           10
+`and`          15
+`&&`           15
+`|`            16
+`^`            17
+`&`            18
+`==`           20
+`===`          20
+`!=`           20
+`!==`          20
+`<`            20
+`>`            20
+`>=`           20
+`<=`           20
+`not in`       20
+`in`           20
+`contains`     20
+`starts with`  20
+`ends with`    20
+`matches`      20
+`..`           25
+`+`            30
+`-`            30
+`~`            40
+`*`            60
+`/`            60
+`%`            60
+`**`           200
+=============  ==========
+
 Built-in Objects and Variables
 ------------------------------