Implode and join in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the implode() function do in PHP?

The implode() function joins array elements into a single string using a specified separator.

beginner

Is join() different from implode() in PHP?

No, join() is an alias of implode(). Both do the same thing: join array elements into a string.

beginner

How do you use implode() to join array elements with a comma?

Use implode(",", $array). This joins all elements of $array separated by commas.

beginner

What happens if you call implode() with an empty array?

It returns an empty string because there are no elements to join.

intermediate

Can implode() be used without specifying a separator?

Yes, if you omit the separator, PHP uses an empty string as default, joining elements directly without anything between them.

What is the output of implode('-', ['a', 'b', 'c'])?

A "a-b-c"

B "abc"

C "a,b,c"

D "a b c"

The implode() function joins array elements with the given separator, here a dash '-'.

Which function is an alias of implode() in PHP?

A explode()

B concat()

C join()

D split()

join() is an alias of implode(), both join array elements into a string.

What does implode() return when given an empty array?

A empty string ""

B false

C null

D array

When the array is empty, implode() returns an empty string.

What is the default separator if none is provided to implode()?

A comma

B empty string

C space

D semicolon

If no separator is given, implode() uses an empty string to join elements.

Which of these is a correct way to join array elements with a space using implode()?

A implode($array, ' ')

B implode($array)

C join($array, ' ')

D implode(' ', $array)

The correct syntax is implode(' ', $array) where the first argument is the separator.

Explain how implode() works and give an example of joining an array with commas.

Think about how you combine words with commas in a sentence.

Describe the relationship between implode() and join() in PHP.

They are like two names for the same thing.