Precedence & Associativity - CPU Material

Define the terms precedence and associativity.

Answer:

When more than one operator is used in an expression, C language has predefined rules of to evaluate expression based on priority of operators. This rule of priority operators is known as precedence of operators.

In arithmetic operators,

Operator	Priority	Associativity
*, /, %	First	Left to Right
+, -	Second	Left to Right

Associativity:

If operators have same priority in one expression then rules define which operator is executed first in which order. This rule is known as associativity.

For example:

If expression contains * and / operators then both have same priority, so associativity rules will be applied for evaluating expression.

Ex:

D = A + B – C.

In this + and – both have same priority

Consider following table for both priority (precedence) and associativity. In this table top most operator has highest priority.

           

Operator	Meaning	Associativity
( ), ++, - -	Parenthesis, postfix increment, postfix decrement	Left to right
++, - -, sizeof	Prefix increment, prefix decrement, sizeof operator	Right to left
*, /, %	Multiplication, division, modulus	Left to right
+, -	Addition, subtraction	Left to right