3.1: Relational Operators and Relational Statements

In C++ programming, followings are commonly used relational operators:

Operator	Name	Example (radius=5)	Result
<	less than	radius<0	false
<=	less than or equal to	radius<=0	false
>	greater than	radius>0	true
>=	greater than or equal to	radius>=0	true
==	equal to	radius==5	true
!=	not equal to	radius!=5	false

We use above relational operators along with numbers, variables, expressions to form a relational statement such as followings:

a>5

i<=10

a!=0

Each relational statement possesses a Boolean value, which is either true or false (1 or 0 equivalently) depending on the logical correctness of the statement. If a relational statement contains variables, the Boolean value of this statement usually depends on the value of the variable. For example, the value of the relational statement

m>5

depends on the value of the variable m. If the value of m is 11, then the value of the statement is true or 1, if the value of m is 0, the value of this relational statement is false or 0.

In C++, a relational statement normally does not appear in a line of code all by itself such as

a=5>2;

A relational statement is often used in a C++ program as a condition in a selection or a looping statement.

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