unset(n) - phpMan

unset(n) Tcl Built-In Commands unset(n)

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NAME
unset - Delete variables

SYNOPSIS
unset ?-nocomplain? ?--? ?name name name ...?
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DESCRIPTION
This command removes one or more variables. Each name is a variable name, specified in
any of the ways acceptable to the set command. If a name refers to an element of an array
then that element is removed without affecting the rest of the array. If a name consists
of an array name with no parenthesized index, then the entire array is deleted. The unset
command returns an empty string as result. If -nocomplain is specified as the first argu-
ment, any possible errors are suppressed. The option may not be abbreviated, in order to
disambiguate it from possible variable names. The option -- indicates the end of the
options, and should be used if you wish to remove a variable with the same name as any of
the options. If an error occurs, any variables after the named one causing the error are
not deleted. An error can occur when the named variable does not exist, or the name
refers to an array element but the variable is a scalar, or the name refers to a variable
in a non-existent namespace.

EXAMPLE
Create an array containing a mapping from some numbers to their squares and remove the
array elements for non-prime numbers:
array set squares {
1 1 6 36
2 4 7 49
3 9 8 64
4 16 9 81
5 25 10 100
}

puts "The squares are:"
parray squares

unset squares(1) squares(4) squares(6)
unset squares(8) squares(9) squares(10)

puts "The prime squares are:"
parray squares