If statement execution flow in PHP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this PHP if-else code?

Look at the PHP code below. What will it print?

PHP

<?php
$number = 10;
if ($number > 10) {
    echo "Greater than 10";
} elseif ($number == 10) {
    echo "Equal to 10";
} else {
    echo "Less than 10";
}
?>

A Equal to 10

B Greater than 10

C Less than 10

D No output

💡 Hint

Check the condition that matches the value 10 exactly.

The variable $number is 10. The first condition ($number > 10) is false. The second condition ($number == 10) is true, so it prints "Equal to 10".

❓ Predict Output

intermediate

What will this PHP code output?

Consider this PHP snippet. What is printed?

PHP

<?php
$value = 0;
if ($value) {
    echo "True";
} else {
    echo "False";
}
?>

A True

B 0

C False

D No output

💡 Hint

Remember how PHP treats 0 in conditions.

In PHP, 0 is considered false in a condition, so the else block runs and prints "False".

🔧 Debug

advanced

Why does this PHP if statement not print anything?

Look at this PHP code. It prints nothing. Why?

PHP

<?php
$score = 75;
if ($score > 80);
{
    echo "Passed";
}
?>

A The semicolon after the if condition ends the if statement early, so the echo always runs.

B The variable $score is not defined correctly.

C The condition is false, so echo is skipped.

D PHP does not allow if statements without braces.

💡 Hint

Check the semicolon after the if condition.

The semicolon after the if condition ends the if statement. The block after it runs always, so "Passed" is printed regardless of the condition.

❓ Predict Output

advanced

What is the output of nested if statements in PHP?

What does this PHP code print?

PHP

<?php
$age = 20;
if ($age > 18) {
    if ($age < 21) {
        echo "Young adult";
    } else {
        echo "Adult";
    }
} else {
    echo "Minor";
}
?>

A No output

B Adult

C Minor

D Young adult

💡 Hint

Check both conditions carefully.

$age is 20, which is greater than 18 and less than 21, so it prints "Young adult".

🧠 Conceptual

expert

How many times does this PHP if-elseif-else chain execute echo?

Consider this PHP code. How many times will it print something?

PHP

<?php
$val = 5;
if ($val > 3) {
    echo "A";
} elseif ($val > 4) {
    echo "B";
} else {
    echo "C";
}
?>

A 2

B 1

C 0

D 3

💡 Hint

Remember that only one block in if-elseif-else runs.

The first condition ($val > 3) is true, so it prints "A" and skips the rest. Only one echo runs.

Practice

1. What does an if statement do in PHP?

easy

A. It defines a function.

B. It repeats code multiple times.

C. It runs code only if a condition is true.

D. It stops the program immediately.

Solution

1. Step 1: Understand the purpose of an if statement

   An if statement checks a condition and runs code only if that condition is true.

2. Step 2: Compare with other options

   Repeating code is done by loops, functions define reusable code, and stopping the program is done by exit or die.

3. Final Answer:

   It runs code only if a condition is true. -> Option C

4. Quick Check:

   If statement = runs code if true [OK]

Hint: If checks condition; runs code only when true [OK]

Common Mistakes:

• Confusing if with loops
• Thinking if defines functions
• Believing if stops the program

2. Which of the following is the correct syntax for an if statement in PHP?

easy

A. if condition { echo 'Yes'; }

B. if (condition) { echo 'Yes'; }

C. if condition: echo 'Yes'; endif;

D. if [condition] { echo 'Yes'; }

Solution

1. Step 1: Recall PHP if statement syntax

   In PHP, the condition must be inside parentheses and the code block inside curly braces.

2. Step 2: Check each option

   if (condition) { echo 'Yes'; } matches the correct syntax: if (condition) { ... }. if condition { echo 'Yes'; } misses parentheses, C uses alternate syntax but missing parentheses, D uses square brackets which is invalid.

3. Final Answer:

   if (condition) { echo 'Yes'; } -> Option B

4. Quick Check:

   Parentheses around condition = correct syntax [OK]

Hint: Always use parentheses around condition in if [OK]

Common Mistakes:

• Omitting parentheses around condition
• Using square brackets instead of parentheses
• Confusing alternate syntax without proper format

3. What will be the output of this PHP code?

$x = 10;
if ($x > 10) {
  echo 'Greater';
} elseif ($x == 10) {
  echo 'Equal';
} else {
  echo 'Less';
}

medium

A. Equal

B. No output

C. Less

D. Greater

Solution

1. Step 1: Evaluate the condition $x > 10

   $x is 10, so $x > 10 is false. The first if block is skipped.

2. Step 2: Check the elseif condition $x == 10

   This condition is true, so it prints 'Equal' and skips the else block.

3. Final Answer:

   Equal -> Option A

4. Quick Check:

   10 == 10 prints Equal [OK]

Hint: Check conditions top to bottom; first true runs [OK]

Common Mistakes:

• Assuming > includes equal
• Ignoring elseif and jumping to else
• Thinking multiple blocks run

4. Find the error in this PHP code:

if $a > 5 {
  echo 'Big';
} else {
  echo 'Small';
}

medium

A. Wrong keyword else

B. Missing semicolon after echo

C. Curly braces not allowed

D. Missing parentheses around condition

Solution

1. Step 1: Check if statement syntax

   In PHP, the condition must be inside parentheses. Here, if $a > 5 is missing parentheses.

2. Step 2: Verify other parts

   Semicolons after echo statements are optional if echo is used as a statement, else keyword is correct, and curly braces are allowed.

3. Final Answer:

   Missing parentheses around condition -> Option D

4. Quick Check:

   Condition must be in parentheses [OK]

Hint: Always put condition inside parentheses in if [OK]

Common Mistakes:

• Forgetting parentheses around condition
• Thinking else keyword is wrong
• Believing semicolon is mandatory after echo

5. Given this PHP code, what will be the output?

$score = 75;
if ($score >= 90) {
  echo 'A';
} elseif ($score >= 80) {
  echo 'B';
} elseif ($score >= 70) {
  echo 'C';
} else {
  echo 'F';
}

hard

A. C

B. A

C. B

D. F

Solution

1. Step 1: Check first condition $score >= 90

   75 is less than 90, so this is false. Skip to next.

2. Step 2: Check second condition $score >= 80

   75 is less than 80, so false again. Skip to next.

3. Step 3: Check third condition $score >= 70

   75 is greater than or equal to 70, so true. It prints 'C' and skips else.

4. Final Answer:

   C -> Option A

5. Quick Check:

   75 >= 70 prints C [OK]

Hint: Check conditions top-down; first true runs [OK]

Common Mistakes:

• Choosing wrong grade for score
• Ignoring elseif order
• Assuming else runs always