Educator

Expression & Operators

• An expression is anything in PHP that has a value.
• An operator takes one or more expressions, called operands , and performs some operation on them to yield another expression.
• Operators can be divided according to how many values they operate on:
  • unary operators: single value
  • binary operators: two values
  • ternary operators: three values
• Assignment operators (=, =>) are binary operators used to assign the value of one expression to another expression .
• There are arithmetic operators for addition, subtraction, multiplication, division, and negation. There is also the modulus (%) operator used for getting the remainder of a division operation.
• The increment/decrement operators are used to increment or decrement their operand by one. They come in both pre and post forms.
• The concatenation operator (.) is used to combine two strings into one.
• PHP provides combined assignment operators for all of the binary arithmetic operators, as well as the concatenation operator.
• Operators have both a precedence and associativity .
• When an expression contains multiple operations, the operations with higher precedence are completed first. If an expression contains two operations of equal precedence , then the associativity of the operations determines which operation is completed first.
• Additional Resources:
  • PHP Manual - Assignment Operators
  • PHP Manual - Arithmetic Operators
  • PHP Manual - Increment/Decrement Operators
  • PHP Manual - Concatenation (String) Operators
  • PHP Manual - Operator Precedence & Associativity Table