PHP Data type null

A special NULL value indicates that a variable has no value. The only possible value for a null type is NULL.

A variable is considered NULL in the following cases:

is assigned a value of NULL.

has not been assigned a value.

Be unset ().

Grammar

A null type has only one value, which is a case-insensitive constant, NULL.

<?php$var = NULL;? >

See Is_null () and unset ().

Convert to NULL

Using the (unset) $var converting a variable to null will not delete the variable or unset its value. Only NULL values are returned.

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