Nested conditional execution in PHP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if-else blocks

What is the output of this PHP code snippet?

PHP

<?php
$score = 75;
if ($score >= 90) {
    echo "Grade: A";
} else {
    if ($score >= 70) {
        echo "Grade: B";
    } else {
        echo "Grade: C";
    }
}
?>

A No output

B Grade: A

C Grade: C

D Grade: B

💡 Hint

Check the first condition and then the nested condition inside the else block.

The score 75 is not >= 90, so the first if fails. Then the nested if checks if score >= 70, which is true, so it prints 'Grade: B'.

❓ Predict Output

intermediate

Nested condition with logical operators

What will this PHP code output?

PHP

<?php
$age = 20;
$hasID = true;
if ($age >= 18) {
    if ($hasID) {
        echo "Access granted";
    } else {
        echo "ID required";
    }
} else {
    echo "Access denied";
}
?>

A No output

B ID required

C Access granted

D Access denied

💡 Hint

Check both conditions inside the nested if.

Age is 20 (>=18) and hasID is true, so both conditions pass and 'Access granted' is printed.

🔧 Debug

advanced

Identify the error in nested condition

What error does this PHP code produce when run?

PHP

<?php
$number = 10;
if ($number > 0) {
    if $number < 20 {
        echo "Number is between 1 and 19";
    }
}
?>

A Parse error: syntax error, unexpected '$number' (T_VARIABLE)

B No output

C Output: Number is between 1 and 19

D Fatal error: Uncaught Error: Undefined variable

💡 Hint

Check the syntax of the nested if statement.

The nested if is missing parentheses around the condition, causing a syntax error.

❓ Predict Output

advanced

Output of nested if-elseif-else

What is the output of this PHP code?

PHP

<?php
$val = 15;
if ($val > 20) {
    echo "Greater than 20";
} elseif ($val > 10) {
    if ($val % 2 == 0) {
        echo "Even and greater than 10";
    } else {
        echo "Odd and greater than 10";
    }
} else {
    echo "10 or less";
}
?>

A Odd and greater than 10

B Even and greater than 10

C Greater than 20

D 10 or less

💡 Hint

Check the elseif condition and then the nested if inside it.

15 is not > 20, but is > 10. 15 % 2 is 1 (odd), so it prints 'Odd and greater than 10'.

🧠 Conceptual

expert

Understanding nested conditional flow

Consider this PHP code snippet. What will be the value of $result after execution?

PHP

<?php
$a = 5;
$b = 10;
if ($a > $b) {
    if ($a - $b > 3) {
        $result = 'A';
    } else {
        $result = 'B';
    }
} else {
    if ($b - $a > 3) {
        $result = 'C';
    } else {
        $result = 'D';
    }
}
?>

A "B"

B "C"

C "A"

D "D"

💡 Hint

Compare values of $a and $b and check the nested conditions carefully.

Since $a (5) is not greater than $b (10), the else block runs. Then $b - $a = 5, which is > 3, so $result is set to 'C'.