The precedence of an operator specifies how "tightly" it binds two expressions together. For example, in the expression 1 + 5 * 3 , the answer is 16 and not 18 because the multiplication ("*") operator has a higher precedence than the addition ("+") operator. Parentheses may be used to force precedence, if necessary.

PHP Operator is a symbol i.e used to perform operations on operands. In simple words, operators are used to perform operations on variables or values. For example: $num=10+20;//+ is the operator and 10,20 are operands.

Precedence is the priority for grouping different types of operators with their operands. Associativity is the left-to-right or right-to-left order for grouping operands to operators that have the same precedence.

The '=>' symbol is used to assign key value pairs in an array. The value of left side is called key and the value of right side is called value of key. It is mostly used in associative array. Example 1: PHP program to create associative array using '=>' symbol.