int 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 nonzero if all listed variables have been set (and thus have a value assigned)

Returns 0 if any listed variable is not assigned a value

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

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

This function is supported only in CSE HTML Validator v11.9910 and later.