How to Check if an Array Value Is One of Several Whitelisted Options in PHP?

Whitelisting Array Values

When working with arrays, ensuring that certain elements adhere to a predefined set of values is crucial for data integrity. In this specific case, you want to determine if the value of $something['say'] is either 'bla' or 'omg'.

Using in_array()

PHP offers the in_array function to simplify this task. It takes two arguments:

• A value to search for (in_array("bla", $yourarray))
• An array to search within ($yourarray)

If the value is found within the array, in_array returns true. This can be applied to your case:

if (in_array("bla", $something)) {
    echo "has bla";
}

Additional Considerations

• Case sensitivity: in_array is case-sensitive by default. If you are dealing with mixed-case values, consider using strtolower() or strtoupper() to standardize the values before checking.
• Associative arrays: The example above assumes that $something is an indexed array. If $something is an associative array, you can specify the key of the element you want to check: in_array("bla", $something['say']).
• Multiple values: To check for multiple whitelisted values, use a foreach loop or array_map.

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