Introduction to PHP – Part 3

Operators

An operator is a type of function which acts on operands often called inputs and produce results. In PHP, there are three types of operators. Increment operator ++ and decrement operator — belongs to the first operator group called unary operator. Unary operator always acts on single operand. The second group called the binary operator acts on more than two operands. .The group is the ternary operator : ? :. This operator is used to select between two expressions depending upon the third one. These operators can be classified in the following ways based on the type of functionality they provides.

Arithmetic Operators

Assignment Operators

Comparison Operators

Logical Operators

Operators Precedence and Associativity

The precedence of an operator specifies which operation is carried first. For example, the result of 2+5*2 is 12 not 14. Here multiplication is evaluated first followed by addition, hence, we say that operator “*” has higher precedence than operator “+”. In some cases parenthesis is used to force the precedence. For instance, the result from same expression with parenthesis like (2+5)*2 will produce result 14.

Associativity decides the order of evaluation of an expression if the operators have equal precedence. If a expression is evaluated from right we called right associativity and for left we say left associativity. The following table shows the precedence of operators having highest precedence. Operators having same associativity are listed in the same line.