Topic: 33 Important PHP Questions for Beginners (with Answers)

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1. What does PHP stand for?
Answer: PHP stands for *PHP: Hypertext Preprocessor*.

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2. What is PHP used for?
Answer: PHP is used to create dynamic web pages and server-side applications.

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3. How do you declare a variable in PHP?
Answer: Variables in PHP start with a $ sign, e.g., $name = "Ali";.

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4. Is PHP case-sensitive?
Answer: Function names are not case-sensitive, but variables are.

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5. What is the difference between `echo` and `print`?
Answer: Both output data. echo is faster and can output multiple strings, while print returns 1.

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6. How do you write comments in PHP?
Answer:

// Single line  
# Another single line  
/* Multi-line */

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7. How do you create a function in PHP?
Answer:

function greet() {
  echo "Hello!";
}

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8. What are the different data types in PHP?
Answer: String, Integer, Float, Boolean, Array, Object, NULL, Resource.

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9. How can you connect PHP to a MySQL database?
Answer: Using mysqli_connect() or new mysqli().

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10. What is a session in PHP?
Answer: A session stores user data on the server across multiple pages.

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11. How do you start a session?
Answer: session_start();

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12. How do you set a cookie in PHP?
Answer: setcookie("name", "value", time()+3600);

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13. How can you check if a variable is set?
Answer: isset($variable);

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14. What is `$_POST` and `$_GET`?
Answer: Superglobals used to collect form data sent via POST or GET methods.

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15. How do you include a file in PHP?
Answer:

include "file.php";  
require "file.php";

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16. Difference between `include` and `require`?
Answer: require will cause a fatal error if the file is missing; include will only raise a warning.

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17. How do you loop through an array?
Answer:

foreach ($array as $value) {
  echo $value;
}

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18. How to define an associative array?
Answer:

$person = ["name" => "Ali", "age" => 25];

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19. What are superglobals in PHP?
Answer: Predefined variables like $_GET, $_POST, $_SESSION, etc.

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20. What is the use of `isset()` and `empty()`?
Answer:
• isset() checks if a variable is set and not null.
• empty() checks if a variable is empty.

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21. How to check if a file exists?
Answer: file_exists("filename.txt");

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22. How to upload a file in PHP?
Answer: Use $_FILES and move_uploaded_file().

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23. What is a constructor in PHP?
Answer: A special method __construct() that runs when an object is created.

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24. What is OOP in PHP?
Answer: Object-Oriented Programming using classes, objects, inheritance, etc.

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25. What are magic constants in PHP?
Answer: Built-in constants like __LINE__, __FILE__, __DIR__.

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26. How to handle errors in PHP?
Answer: Using try...catch, error_reporting(), and set_error_handler().

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27. What is the difference between `==` and `===`?
Answer:
• == checks value only.
• === checks value and type.

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28. How to redirect a user in PHP?
Answer:

header("Location: page.php");

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29. How to sanitize user input?
Answer: Use htmlspecialchars(), strip_tags(), trim().

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30. How do you close a MySQL connection?
Answer: $conn->close();

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31. What is `explode()` in PHP?
Answer: Splits a string into an array using a delimiter.

explode(",", "one,two,three");

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32. How do you hash passwords in PHP?
Answer:

password_hash("123456", PASSWORD_DEFAULT);

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33. What version of PHP should you use?
Answer: Always use the latest stable version (e.g., PHP 8.2+) for performance and security.

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#PHP #InterviewQuestions #Beginners #PHPTutorial #WebDevelopment

https://t.iss.one/Ebooks2023

# 📚 JavaScript Tutorial - Part 2/10: Control Flow & Functions
#JavaScript #WebDev #Programming #Beginners

Welcome to Part 2 of our JavaScript series! Today we'll master decision-making and functions - the building blocks of programming logic.

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## 🔹 Conditional Statements
Control program flow based on conditions.

### 1. if-else Statement

let age = 18;

if (age >= 18) {
    console.log("You're an adult");
} else {
    console.log("You're a minor");
}

### 2. Ternary Operator (Shorthand if-else)

let message = (age >= 18) ? "Adult" : "Minor";
console.log(message);

### 3. switch-case Statement

let day = 3;
let dayName;

switch(day) {
    case 1: dayName = "Monday"; break;
    case 2: dayName = "Tuesday"; break;
    case 3: dayName = "Wednesday"; break;
    default: dayName = "Unknown";
}

console.log(dayName); // "Wednesday"

---

## 🔹 Loops
Execute code repeatedly.

### 1. for Loop

for (let i = 1; i <= 5; i++) {
    console.log(`Count: ${i}`);
}
// Output: 1, 2, 3, 4, 5

### 2. while Loop

let count = 1;
while (count <= 5) {
    console.log(count);
    count++;
}

### 3. do-while Loop

let x = 1;
do {
    console.log(x);
    x++;
} while (x <= 5);

### 4. for...of Loop (Arrays)

const colors = ["red", "green", "blue"];
for (const color of colors) {
    console.log(color);
}

### 5. for...in Loop (Objects)

const person = {name: "Ali", age: 25};
for (const key in person) {
    console.log(`${key}: ${person[key]}`);
}

---

## 🔹 Functions
Reusable blocks of code.

### 1. Function Declaration

function greet(name) {
    return `Hello, ${name}!`;
}
console.log(greet("Ali")); // "Hello, Ali!"

### 2. Function Expression

const square = function(x) {
    return x * x;
};
console.log(square(5)); // 25

### 3. Arrow Functions (ES6+)

const add = (a, b) => a + b;
console.log(add(2, 3)); // 5

### 4. Default Parameters

function createUser(name, role = "user") {
    console.log(`${name} is a ${role}`);
}
createUser("Ali"); // "Ali is a user"

### 5. Rest Parameters

function sum(...numbers) {
    return numbers.reduce((total, num) => total + num, 0);
}
console.log(sum(1, 2, 3)); // 6

---

## 🔹 Practical Example: Grade Calculator

function calculateGrade(score) {
    if (score >= 90) return "A";
    else if (score >= 80) return "B";
    else if (score >= 70) return "C";
    else return "F";
}

const studentScore = 85;
console.log(`Grade: ${calculateGrade(studentScore)}`); // "Grade: B"

---

## 🔹 Scope in JavaScript
### 1. Global Scope

const globalVar = "I'm global";

function test() {
    console.log(globalVar); // Accessible
}

### 2. Function Scope (var)

function test() {
    var functionVar = "I'm function-scoped";
}
console.log(functionVar); // Error: Not accessible

### 3. Block Scope (let/const)

if (true) {
    let blockVar = "I'm block-scoped";
}
console.log(blockVar); // Error: Not accessible

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## 🔹 Error Handling
### 1. try-catch-finally

try {
    // Risky code
    nonExistentFunction();
} catch (error) {
    console.log("Error occurred:", error.message);
} finally {
    console.log("This always executes");
}

### 2. Throwing Custom Errors

function divide(a, b) {
    if (b === 0) throw new Error("Cannot divide by zero!");
    return a / b;
}

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## 🔹 Best Practices
1. Use strict equality (===) over ==
2. Prefer const/let over var
3. Keep functions small/single-purpose
4. Always handle errors
5. Use descriptive names for functions/variables

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### 📌 What's Next?
In Part 3, we'll cover:
➡️ Arrays & Array Methods
➡️ Objects & JSON
➡️ Destructuring

#LearnJavaScript #CodingBasics #WebDevelopment 🚀

Practice Exercise:
1. Create a function to check if a number is even/odd
2. Write a loop that prints prime numbers up to 20
3. Make a temperature converter function (Celsius ↔️ Fahrenheit)