Relational Operators : Relational operators are used in Boolean conditions or expressions, that return either true or false.
The relational operators returns zero values or non-zero values. The zero values is taken as false, while the non-zero value is taken as true.
A simple relational expression contains only one relational operator and takes the following form : ,/p>
ae - 1 and ae - 2 are arithmetic expressions, which may be simple constants, variables or combination of them and arithmetic operators.
C supports six Relational operators and are as follows :
|<=||less than or equal to|
|>=||greater than or equal to|
|==||is equal to|
|!=||is not equal to|
Relational operators are used to compare two quantities.,/p>
Relational operators are binary operators, because they act on two operands.
The operators <, <=, >, >= will be given the highest priority over ==, !=
when equal priority operators are there in an expression, the operators will be evaluated from left to right i.e they follow left to right associativity.
4.5 <= 10 true
4.5 < -10 false
-35 >= 0 false
10 < 7 + 5 true
(10+5) == (3*5) true
a + b == c + d true, only if the sum of values of a and b is equal to the sum of values of c and d.
When arithmetic expressions are used on either side of a relational operator, then the arithmetic expressions will be evaluated first and then the results will be compared. That is, arithmetic operators have a higher priority over relational operators.
Relational expressions are used in decision statements such as if and while to decide the course of action of a running program.
Relational Operator Complements :
Among the six relational operators, each one is a complement of another operator.
< is complement of >=
== is complement of !=
We can simplify an expression involving the not and the relational operators using the complements as shown below :
|Actual one||Simplified one|
|!(x + y)||x >= y|
|!(x > y)||x <= y|
|!(x != y)||x == y|
|!(x <= y)||x > y|
|!(x >= y)||x < y|
|!(x == y)||x != y|