Relational patterns in C Sharp (C#) - Step-by-Step Execution

Concept Flow - Relational patterns

Start with a value

↓

Apply relational pattern

↓

Check if value matches condition

Yes No↓

Execute True

↓

End

Relational patterns check if a value meets a condition like >, <, >=, <=, ==, or != and then choose what to do based on that.

Execution Sample

C Sharp (C#)

int x = 7;
if (x is > 5 and < 10)
{
    Console.WriteLine("x is between 6 and 9");
}

This code checks if x is greater than 5 and less than 10, then prints a message.

Execution Table

Step	Variable x	Condition Checked	Result	Branch Taken	Output
1	7	x > 5	True	Continue
2	7	x < 10	True	Execute True branch	x is between 6 and 9
3	7	End	-	-	-

💡 Both conditions true, so the true branch runs and then execution ends.

Variable Tracker

Variable	Start	After Step 1	After Step 2	Final
x	7	7	7	7

Key Moments - 2 Insights

Why do we check both conditions separately in the relational pattern?

Because the pattern uses 'and', both conditions must be true for the whole pattern to be true, as shown in steps 1 and 2 of the execution_table.

What happens if the first condition is false?

The second condition is not checked and the false branch runs, but in this example, the first condition is true, so both are checked.

Visual Quiz - 3 Questions

Look at the execution_table, what is the result of the condition 'x > 5' at step 1?

A Not evaluated

B True

C False

D Error

💡 Hint

Check the 'Result' column at step 1 in the execution_table.

At which step does the program decide to execute the true branch?

A Step 2

B Step 1

C Step 3

D Before step 1

💡 Hint

Look at the 'Branch Taken' column in the execution_table.

If x was 4, how would the execution_table change at step 1?

A Condition 'x > 5' would be True

B Condition 'x < 10' would be False

C Condition 'x > 5' would be False

D Output would be 'x is between 6 and 9'

💡 Hint

Refer to the 'Condition Checked' and 'Result' columns for step 1.

Concept Snapshot

Relational patterns check if a value meets a condition like >, <, >=, <=, ==, or !=.
Syntax example: if (x is > 5 and < 10) { ... }
Both conditions must be true if combined with 'and'.
Used to simplify multiple comparisons in one pattern.
Executes code based on whether the pattern matches.

Full Transcript

Relational patterns in C# let you check if a value meets conditions like greater than or less than. The code example shows checking if x is greater than 5 and less than 10. The execution flow first checks if x > 5, which is true for x=7, then checks if x < 10, also true. Because both are true, the program runs the true branch and prints the message. Variables stay the same during checks. If any condition fails, the false branch runs instead. This helps write clear and simple condition checks.