Gettype and typeof checks in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the gettype() function do in PHP?

The gettype() function returns the type of a variable as a string, like 'integer', 'string', or 'array'.

beginner

Is there a typeof operator in PHP like in JavaScript?

No, PHP does not have a typeof operator. Instead, it uses functions like gettype() or is_*() functions to check types.

beginner

How can you check if a variable is an integer in PHP?

You can use is_int($var) which returns true if $var is an integer.

beginner

What type string does gettype() return for a boolean variable?

It returns the string 'boolean'.

intermediate

Why might you prefer is_*() functions over gettype() for type checking?

Because is_*() functions return a boolean (true/false), making it easier to write conditions, while gettype() returns a string that you must compare.

What does gettype(123) return in PHP?

A 'integer'

B 'string'

C 'number'

D 'int'

gettype() returns 'integer' for whole numbers.

Which function checks if a variable is a string in PHP?

A gettype()

B is_str()

C typeof()

D is_string()

is_string() returns true if the variable is a string.

Does PHP have a typeof operator like JavaScript?

A Yes, it works the same way

B No, PHP uses <code>gettype()</code> instead

C Yes, but it returns different values

D No, PHP does not support type checking

PHP uses gettype() and is_*() functions for type checking.

What will is_bool(true) return?

A null

B false

C true

D 1

is_bool() returns true if the variable is boolean.

Which of these is NOT a valid return value of gettype()?

A 'number'

B 'double'

C 'array'

D 'object'

'number' is not a valid return value; PHP uses 'integer' or 'double' instead.

Explain how to check the type of a variable in PHP and the difference between gettype() and is_*() functions.

Think about how PHP tells you what type a variable is and how you can test it in conditions.

Describe why PHP does not have a typeof operator and how you can achieve similar functionality.

Compare PHP and JavaScript type checking methods.