Part of the dict command introduced in Tcl 8.5. See [L1 ] for documentation.
[dict unset] removes one element from a dict or nested dict, given
The variable is modified, and the new value is also returned. If the given key doesn't exist in the dict, no change is made. If a key path is given, all keys except the last must exist.
% # Simple example:
% set data {a 1 b 2}
a 1 b 2
% dict unset data a ;# Remove key "a" and its corresponding value "1"
b 2
% set data ;# Verify that variable is modified.
b 2
% dict unset data nonexistent ;# Check nonexistent key handling
b 2% # Example using nested dicts:
% set data {row1 {col1 val11 col2 val12} row2 {col1 val21 col2 val22}}
row1 {col1 val11 col2 val12} row2 {col1 val21 col2 val22}
% dict unset data row2 col2 ;# Remove element "col2" in nested dict "row2"
row1 {col1 val11 col2 val12} row2 {col1 val21}
% dict unset data row1 ;# Remove element "row1"
row2 {col1 val21}
% set data ;# Verify again that variable is modified
row2 {col1 val21}
% dict unset data row2 col2 ;# Check nonexistent key handling
row2 {col1 val21}
% dict unset data row1 col2 ;# Check nonexistent nested dict handling
key "row1" not known in dictionary