PHP Syntax and Basics

Question 1

Q: What does PHP stand for?

Answer 1

A: PHP: Hypertext Preprocessor.

Question 2

Q: What is PHP primarily used for?

Answer 2

A: Server-side scripting for web development.

Question 3

Q: How do you start and end a block of PHP code?

Answer 3

A: <?php to start and ?> to end.

Question 4

Q: What is the correct way to output text in PHP?

Answer 4

A: Using echo or print.

Question 5

Q: How do you add a single-line comment in PHP?

Answer 5

A: Use // or #.

Question 6

Q: How do you declare a variable in PHP?

Answer 6

A: Use the $ symbol, e.g., $variable_name = “value”;.

Question 7

Q: What are the common data types in PHP?

Answer 7

A: String, Integer, Float, Boolean, Array, Object, NULL.

Question 8

Q: What function is used to get the data type of a variable?

Answer 8

A: gettype().

Question 9

Q: How do you check if a variable is set?

Answer 9

A: Use the isset() function.

Question 10

Q: How do you unset a variable in PHP?

Answer 10

A: Use the unset() function.

Question 11

Q: How do you define a constant in PHP?

Answer 11

A: Using the define() function.

Question 12

Q: Can constants be changed after they are set?

Answer 12

A: No, constants are immutable.

Question 13

Q: What is the correct syntax for defining a constant?

Answer 13

A: define(“CONSTANT_NAME”, “value”);.

Question 14

Q: How do you access a constant?

Answer 14

A: Use the constant name directly, e.g., CONSTANT_NAME.

Question 15

Q: What is the difference between define() and const?

Answer 15

A: const is used for class constants and must be defined in the global scope.

Question 16

Q: What are the arithmetic operators in PHP?

Answer 16

A: +, -, *, /, %.

Question 17

Q: What is the concatenation operator in PHP?

Answer 17

A: . (dot).

Question 18

Q: What are the comparison operators in PHP?

Answer 18

A: ==, ===, !=, !==, <, >, <=, >=.

Question 19

Q: What is the spaceship operator in PHP, and what does it do?

Answer 19

A: <=>, it returns -1, 0, or 1 depending on the comparison.

Question 20

Q: What are logical operators in PHP?

Answer 20

A: &&, ||, !, and, or.

Question 21

Q: What is the syntax for an if statement in PHP?

Answer 21

if (condition) {
// Code to execute
}

Question 22

Q: How do you write a switch statement in PHP?

Answer 22

switch (variable) {
case “value1”:
// Code
break;
default:
// Code
}

Question 23

Q: How do you write a while loop in PHP?

Answer 23

while (condition) {
// Code to execute
}

Question 24

Q: How do you write a for loop in PHP?

Answer 24

for ($i = 0; $i < 10; $i++) {
// Code
}

Question 25

Q: What is the difference between break and continue in loops?

Answer 25

A: break exits the loop, while continue skips to the next iteration.

Question 26

Q: How do you define a function in PHP?

Answer 26

function functionName() {
// Code
}

Question 27

Q: How do you return a value from a function?

Answer 27

A: Use the return keyword.

Question 28

Q: Can PHP functions have default arguments?

Answer 28

A: Yes, e.g., function example($arg = “default”).

Question 29

Q: How do you pass arguments by reference to a function?

Answer 29

A: Use & before the variable name in the function declaration.

Question 30

Q: What is an anonymous function in PHP?

Answer 30

A: A function without a name, created using the function keyword.

Question 31

Q: How do you create an indexed array in PHP?

Answer 31

A: $array = array(“value1”, “value2”);.

Question 32

Q: How do you create an associative array in PHP?

Answer 32

A: $array = array(“key1” => “value1”, “key2” => “value2”);.

Question 33

Q: What function is used to loop through an array?

Answer 33

A: foreach.

Question 34

Q: How do you add an element to an array?

Answer 34

A: $array[] = “new value”;.

Question 35

Q: What function checks if a value exists in an array?

Answer 35

A: in_array().

Question 36

Q: What is the difference between single and double quotes in PHP?

Answer 36

A: Double quotes parse variables, single quotes do not.

Question 37

Q: How do you find the length of a string in PHP?

Answer 37

A: Use the strlen() function.

Question 38

Q: How do you replace a substring in PHP?

Answer 38

A: Use the str_replace() function.

Question 39

Q: How do you convert a string to lowercase in PHP?

Answer 39

A: Use the strtolower() function.

Question 40

Q: How do you find the position of a substring in a string?

Answer 40

A: Use the strpos() function.