bool isSet($var1[, $var2...])

$varx - the names of the variables to check to see if they are all set (that they all have a value)

Returns true if all listed variables have been set (and thus have a value assigned)

Returns false if any listed variable is not assigned a value

Example: to see if $varname is defined, use isSet($varname), DO NOT use isSet('varname')

An empty string is considered a value for the purposes of this function.

It is recommended that this function be used instead of isDefined().

See also: has[No]Value()

This function is supported by CSS HTML Validator v11.9910 and later.

bool isSetAny($var1[, $var2...])

This function is like isSet() except that it returns true if any one of the listed variables is set and false only if none of the listed variables are set.

This function is supported by CSS HTML Validator v16.9904 and later.