What are the best practices for handling undefined variables in PHP to avoid errors like "Undefined variable"?

When dealing with undefined variables in PHP to avoid errors like "Undefined variable", it is best practice to check if the variable is set before using it. This can be done using the isset() function or by using the null coalescing operator (??) to provide a default value if the variable is not set. 

// Using isset() function to check if the variable is set
$variable = isset($undefinedVariable) ? $undefinedVariable : '';

// Using null coalescing operator to provide a default value
$variable = $undefinedVariable ?? '';

Keywords

PHP error handling undefined variables isset error_reporting

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