6.5.2 Relational operators

Relational Operators in Programs

Relational operators compare two values and return a Boolean result (True or False). They are the building blocks of every condition in if statements and loops.

Meaning	Python	C#	VB.NET
Equal to	`==`	`==`	`=`
Not equal to	`!=`	`!=`	`<>`
Less than	`<`	`<`	`<`
Less than or equal to	`<=`	`<=`	`<=`
Greater than	`>`	`>`	`>`
Greater than or equal to	`>=`	`>=`	`>=`

VB.NET uses = for both assignment and equality testing (context determines meaning). Python and C# use = for assignment only; equality is always ==.

Relational Operators in Context

score = int(input("Enter score: "))
PASS  = 60
MERIT = 75
DIST  = 90

# == and != in selection
if score == 100:
    print("Perfect score!")
elif score != 0 and score >= DIST:
    print("Distinction")
elif score >= MERIT:
    print("Merit")
elif score >= PASS:
    print("Pass")
else:
    print("Not yet — keep going")

# < and <= in a while loop (input validation)
attempts = 0
MAX = 3
while attempts < MAX:
    pin = input("Enter PIN: ")
    if pin == "1234":
        print("Unlocked")
        break
    attempts += 1
if attempts >= MAX:
    print("Locked")

int score = int.Parse(Console.ReadLine());
const int PASS = 60, MERIT = 75, DIST = 90;

if (score == 100)
    Console.WriteLine("Perfect score!");
else if (score != 0 && score >= DIST)
    Console.WriteLine("Distinction");
else if (score >= MERIT)
    Console.WriteLine("Merit");
else if (score >= PASS)
    Console.WriteLine("Pass");
else
    Console.WriteLine("Not yet — keep going");

int attempts = 0;
const int MAX = 3;
while (attempts < MAX) {
    string pin = Console.ReadLine();
    if (pin == "1234") { Console.WriteLine("Unlocked"); break; }
    attempts++;
}
if (attempts >= MAX)
    Console.WriteLine("Locked");

Dim score As Integer = Integer.Parse(Console.ReadLine())
Const PASS As Integer = 60
Const MERIT As Integer = 75
Const DIST As Integer = 90

If score = 100 Then
    Console.WriteLine("Perfect score!")
ElseIf score <> 0 AndAlso score >= DIST Then
    Console.WriteLine("Distinction")
ElseIf score >= MERIT Then
    Console.WriteLine("Merit")
ElseIf score >= PASS Then
    Console.WriteLine("Pass")
Else
    Console.WriteLine("Not yet — keep going")
End If

Dim attempts As Integer = 0
Const MAX As Integer = 3
Do While attempts < MAX
    Dim pin As String = Console.ReadLine()
    If pin = "1234" Then
        Console.WriteLine("Unlocked")
        Exit Do
    End If
    attempts += 1
Loop
If attempts >= MAX Then Console.WriteLine("Locked")

Key Takeaways

Relational operators return True or False — they are used in if conditions and while loop conditions.
Python/C#: equality is ==; assignment is =. Never mix them up.
VB.NET: = serves as both assignment and equality; <> is not-equal.
Boundary conditions: use >= not > when the limit value itself should be included.