PHP Question: Include And Require Files

13th April 2011 - 1 minute read time

Note: This post is over a year old and so the information contained here might be out of date. If you do spot something please leave a comment and I will endeavour to correct.

Question

What's the difference between include() and require()?

Answer

The answer is how they both deal with failures. If the file is not found by require(), it will cause a fatal error and halt the execution of the script. If the file is not found by include(), a warning will be issued, but execution will continue.

This is an important distinction as if your script uses bit of code in an external file, and it isn't there, then you can either chose the make the script stop, or continue and fail gracefully.

PHP

Comments

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arent they identical... apart from include() on fail produces a warning and the rest of the script can continue, whereas require() on fail will produce an error and the script will cease

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The difference between them is that require() will cause the script to fail if the file cannot be included, while include() will not.

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include() produces a warning in the event the file is not available.

require() produces a fatal error in the event the file is not available.

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I didn't know about this. I could have looked in the docs, but since you brought it up, I wanted to find out from you.

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