PHP dynamic typing behavior - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does dynamic typing mean in PHP?

Dynamic typing means PHP variables do not have a fixed type. The type is determined automatically based on the value assigned to the variable.

beginner

How does PHP handle adding a string and an integer?

PHP converts the string to a number if possible, then adds the two numbers. For example, '5' + 3 results in 8.

beginner

What happens if you use a variable before assigning a value in PHP?

PHP treats the variable as NULL and may show a warning depending on error settings.

intermediate

Explain type juggling in PHP.

Type juggling is PHP automatically converting types when performing operations, like converting strings to numbers or booleans to integers.

intermediate

Can you force a variable to a specific type in PHP? How?

Yes, by using type casting like (int), (string), (bool), etc. For example, (int) '123' converts the string to an integer.

What type will the variable have after this code? <br> $var = 10;

A Float

B Integer

C Boolean

D String

Assigning 10 makes $var an integer type.

What is the result of '5' + 2 in PHP?

A Error

B '52'

C 7

D '5 2'

PHP converts '5' to integer 5 and adds 2, resulting in 7.

What does PHP do if you add a boolean TRUE to an integer 3?

A TRUE3

B 3

C Error

D 4

TRUE is converted to 1, so 1 + 3 = 4.

Which of these is NOT a way to cast a variable to a type in PHP?

A (var)

B (string)

C (float)

D (int)

(var) is not a valid type cast in PHP.

If you assign $x = 'abc'; and then add 5 to $x, what is the result?

A 5

B 'abc5'

C Error

D 0

PHP converts 'abc' to 0 when used in arithmetic, so 0 + 5 = 5.

Explain how PHP's dynamic typing affects variable usage and operations.

Think about how PHP changes variable types based on context.

Describe how you can control or change variable types explicitly in PHP.

Consider how to force a variable to be a certain type.