March 29, 2026 in Php
PHP Basics Interview Questions
🧾 PHP Basics – Interview Questions
🔹 1. Basic Questions (Very Important)
1️⃣ What is PHP?
👉 PHP (Hypertext Preprocessor) is a server-side scripting language used to build dynamic websites.
2️⃣ What are variables in PHP?
👉 Variables store data and start with $
Example:
$name = "Aditya";3️⃣ Is PHP case-sensitive?
👉 Variables are case-sensitive ($name ≠ $Name)
👉 Keywords are NOT case-sensitive (echo = ECHO)
4️⃣ What are data types in PHP?
👉 Common types:
- String
- Integer
- Float
- Boolean
- Array
- Object
5️⃣ Difference between echo and print?
| echo | |
|---|---|
| Faster | Slower |
| No return value | Returns 1 |
| Can print multiple values | Only one |
🔹 2. Intermediate Questions
6️⃣ What is a constant in PHP?
👉 A constant is a fixed value that cannot be changed.
define("SITE", "SOA Technology");7️⃣ What is the difference between == and ===?
==→ compares value===→ compares value + data type
10 == "10" // true
10 === "10" // false8️⃣ What are operators in PHP?
👉 Symbols used to perform operations.
Types:
- Arithmetic (
+ - * / %) - Comparison (
== != > <) - Logical (
&& || !)
9️⃣ What is the use of var_dump()?
👉 It shows data type + value
var_dump(10); // int(10)🔟 What are comments in PHP?
👉 Used to explain code
// single line
# single line/*
multi-line
*/🔹 3. Tricky Questions (Asked in Interviews)
1️⃣1️⃣ What will be the output?
$x = 5;
echo $x++;👉 Output: 5 (post-increment)
1️⃣2️⃣ What will be the output?
$x = 5;
echo ++$x;👉 Output: 6 (pre-increment)
1️⃣3️⃣ Difference between single quotes and double quotes?
' '→ No variable parsing" "→ Variables are parsed
$name = "Aditya";echo 'Hello $name'; // Hello $name
echo "Hello $name"; // Hello Aditya1️⃣4️⃣ Can we redeclare a constant?
👉 ❌ No
1️⃣5️⃣ What happens if you use an undefined variable?
👉 PHP shows a warning/notice
🔹 4. Practical / Coding Questions
1️⃣6️⃣ Write a program to check even or odd
$num = 4;
if($num % 2 == 0){
echo "Even";
} else {
echo "Odd";
}1️⃣7️⃣ Swap two numbers
$a = 5;
$b = 10;$a = $a + $b;
$b = $a - $b;
$a = $a - $b;1️⃣8️⃣ Find largest of two numbers
$a = 10;
$b = 20;echo ($a > $b) ? $a : $b;🔥 Pro Interview Tips
- Always explain why, not just code
- Be clear on
== vs ===(very important) - Know basic syntax + output prediction
- Practice small programs
