PHP Manualunset(PHP 4, PHP 5) unset — Unset a given variable Descriptionunset() destroys the specified variables. The behavior of unset() inside of a function can vary depending on what type of variable you are attempting to destroy. If a globalized variable is unset() inside of a function, only the local variable is destroyed. The variable in the calling environment will retain the same value as before unset() was called.
<?php The above example will output:
bar To unset() a global variable inside of a function, then use the $GLOBALS array to do so:
<?php If a variable that is PASSED BY REFERENCE is unset() inside of a function, only the local variable is destroyed. The variable in the calling environment will retain the same value as before unset() was called.
<?php The above example will output:
something something If a static variable is unset() inside of a function, unset() destroys the variable only in the context of the rest of a function. Following calls will restore the previous value of a variable.
<?php The above example will output:
Before unset: 1, after unset: 23 Before unset: 2, after unset: 23 Before unset: 3, after unset: 23 Parameters
Return ValuesNo value is returned. Changelog
Examples
Example #1 unset() example
<?php Example #2 Using (unset) casting (unset) casting is often confused with the unset() function. (unset) casting serves only as a NULL-type cast, for completeness. It does not alter the variable it's casting.
<?php The above example will output: NULL string(6) "Felipe" Notes
See Also
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