Common php syntax errors

To fix this, add a closing bracket after the condition:

3. Typos

Typos are a common syntax error in PHP. For example, misspelling a variable or function name can cause a syntax error. For example:

The above code will generate the following error:

Notice: Undefined variable: messsage in /path/to/file.php on line 2 

To fix this, correct the variable name:

Tips for Avoiding Syntax Errors

Here are some tips for avoiding syntax errors in PHP:

• Use a text editor or integrated development environment (IDE) that highlights syntax errors.
• Enable error reporting in the PHP configuration file to receive detailed error messages.
• Check your code for missing semicolons, brackets, and typos.
• Test your code frequently to catch and fix errors early on.

By following these tips and being mindful of common syntax errors, you can write clean and error-free PHP code.

Conclusion

In conclusion, syntax errors are common in PHP, but they can be easily avoided. By taking the time to check your code for missing semicolons, brackets, and typos, you can ensure that your code runs smoothly. Additionally, it is important to use an IDE or text editor that highlights errors and enabling error reporting to receive detailed error messages. Following these tips will help you write clean and efficient PHP code.

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PHP parse/syntax errors; and how to solve them

I think this topic is totally overdiscussed/overcomplicated. Using an IDE is THE way to go to completely avoid any syntax errors. I would even say that working without an IDE is kind of unprofessional. Why? Because modern IDEs check your syntax after every character you type. When you code and your entire line turns red, and a big warning notice shows you the exact type and the exact position of the syntax error, then there's absolutely no need to search for another solution.

Using a syntax-checking IDE means:

You'll (effectively) never run into syntax errors again, simply because you see them right as you type. Seriously.

Excellent IDEs with syntax check (all of them are available for Linux, Windows and Mac):

1. NetBeans [free]
2. PHPStorm [$199 USD]
3. Eclipse with PHP Plugin [free]
4. Sublime [$80 USD] (mainly a text editor, but expandable with plugins, like PHP Syntax Parser)

Unexpected [

These days, the unexpected [ array bracket is commonly seen on outdated PHP versions. The short array syntax is available since PHP >= 5.4. Older installations only support array() .

$php53 = array(1, 2, 3); $php54 = [1, 2, 3]; ⇑ 

Array function result dereferencing is likewise not available for older PHP versions:

Reference - What does this error mean in PHP? - "Syntax error, unexpected \[ " shows the most common and practical workarounds.

Though, you're always better off just upgrading your PHP installation. For shared webhosting plans, first research if e.g. SetHandler php56-fcgi can be used to enable a newer runtime.

• PHP syntax for dereferencing function result → possible as of PHP 5.4
• PHP syntax error, unexpected '['
• Shorthand for arrays: is there a literal syntax like <> or []?
• PHP 5.3.10 vs PHP 5.5.3 syntax error unexpected '['
• PHP Difference between array() and []
• PHP Array Syntax Parse Error Left Square Bracket "["

BTW, there are also preprocessors and PHP 5.4 syntax down-converters if you're really clingy with older + slower PHP versions.

Other causes for Unexpected [ syntax errors

If it's not the PHP version mismatch, then it's oftentimes a plain typo or newcomer syntax mistake:

You can't use array property declarations/expressions in classes, not even in PHP 7.

Unexpected ] closing square bracket

This is somewhat rarer, but there are also syntax accidents with the terminating array ] bracket.

Again mismatches with ) parentheses or > curly braces are common:

What are the syntax errors?

PHP belongs to the C-style and imperative programming languages. It has rigid grammar rules, which it cannot recover from when encountering misplaced symbols or identifiers. It can't guess your coding intentions.

Most important tips

There are a few basic precautions you can always take:

• Use proper code indentation, or adopt any lofty coding style. Readability prevents irregularities.
• Use an IDE or editor for PHP with syntax highlighting. Which also help with parentheses/bracket balancing.
• Read the language reference and examples in the manual. Twice, to become somewhat proficient.

How to interpret parser errors

A typical syntax error message reads:

Parse error: syntax error, unexpected T_STRING, expecting ' ; ' in file.php on line 217

Which lists the possible location of a syntax mistake. See the mentioned file name and line number.

A moniker such as T_STRING explains which symbol the parser/tokenizer couldn't process finally. This isn't necessarily the cause of the syntax mistake, however.

It's important to look into previous code lines as well. Often syntax errors are just mishaps that happened earlier. The error line number is just where the parser conclusively gave up to process it all.

Solving syntax errors

There are many approaches to narrow down and fix syntax hiccups.

• Open the mentioned source file. Look at the mentioned code line.
  • For runaway strings and misplaced operators, this is usually where you find the culprit.
  • Read the line left to right and imagine what each symbol does.
  • In particular, missing ; semicolons are missing at the previous line ends/statement. (At least from the stylistic viewpoint. )
  • If < code blocks >are incorrectly closed or nested, you may need to investigate even further up the source code. Use proper code indentation to simplify that.
  • Strings and variables and constants should all have different colors.
  • Operators +-*/. should be tinted distinct as well. Else they might be in the wrong context.
  • If you see string colorization extend too far or too short, then you have found an unescaped or missing closing " or ' string marker.
  • Having two same-colored punctuation characters next to each other can also mean trouble. Usually, operators are lone if it's not ++ , -- , or parentheses following an operator. Two strings/identifiers directly following each other are incorrect in most contexts.
  1. The code you can easily identify as correct,
  2. The parts you're unsure about,
  3. And the lines which the parser complains about.

  Partitioning up long code blocks really helps to locate the origin of syntax errors.

  • If you can't isolate the problem source, start to comment out (and thus temporarily remove) blocks of code.
  • As soon as you got rid of the parsing error, you have found the problem source. Look more closely there.
  • Sometimes you want to temporarily remove complete function/method blocks. (In case of unmatched curly braces and wrongly indented code.)
  • When you can't resolve the syntax issue, try to rewrite the commented out sections from scratch.
  • The ternary ? : condition operator can compact code and is useful indeed. But it doesn't aid readability in all cases. Prefer plain if statements while unversed.
  • PHP's alternative syntax ( if: / elseif: / endif; ) is common for templates, but arguably less easy to follow than normal < code >blocks.
  • Missing semicolons ; for terminating statements/lines.
  • Mismatched string quotes for " or ' and unescaped quotes within.
  • Forgotten operators, in particular for the string . concatenation.
  • Unbalanced ( parentheses ) . Count them in the reported line. Are there an equal number of them?
  • If you make one issue go away, but other crops up in some code below, you're mostly on the right path.
  • If after editing a new syntax error crops up in the same line, then your attempted change was possibly a failure. (Not always though.)
  • Adopt a source code versioning system. You can always view a diff of the broken and last working version. Which might be enlightening as to what the syntax problem is.
  • Try grep --color -P -n "\[\x80-\xFF\]" file.php as the first measure to find non-ASCII symbols.
  • In particular BOMs, zero-width spaces, or non-breaking spaces, and smart quotes regularly can find their way into the source code.
  • PHP just honors \n newlines, not \r carriage returns.
  • Which is occasionally an issue for MacOS users (even on OS X for misconfigured editors).
  • It often only surfaces as an issue when single-line // or # comments are used. Multiline /*. */ comments do seldom disturb the parser when linebreaks get ignored.
  • You are looking at the wrong file!
  • Or your code contained invisible stray Unicode (see above). You can easily find out: Just copy your code back from the web form into your text editor.
  • php -v for the command line interpreter

  Those aren't necessarily the same. In particular when working with frameworks, you will them to match up.

  If all else fails, you can always google your error message. Syntax symbols aren't as easy to search for (Stack Overflow itself is indexed by SymbolHound though). Therefore it may take looking through a few more pages before you find something relevant.

  • PHP Debugging Basics by David Sklar
  • Fixing PHP Errors by Jason McCreary
  • PHP Errors – 10 Common Mistakes by Mario Lurig
  • Common PHP Errors and Solutions
  • How to Troubleshoot and Fix your WordPress Website
  • A Guide To PHP Error Messages For Designers - Smashing Magazine

  White screen of death

  If your website is just blank, then typically a syntax error is the cause. Enable their display with:

  In your php.ini generally, or via .htaccess for mod_php, or even .user.ini with FastCGI setups.

  Enabling it within the broken script is too late because PHP can't even interpret/run the first line. A quick workaround is crafting a wrapper script, say test.php :

  Then invoke the failing code by accessing this wrapper script.

  It also helps to enable PHP's error_log and look into your webserver's error.log when a script crashes with HTTP 500 responses.

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