lappend
Appends values to a list variable.
Syntax
tcl
lappend varName ?value value value ...?Parameters
- varName: Name of the variable containing the list
- value: Optional values to append to the list
Description
The lappend command appends values to a list stored in a variable. Each value is appended as a separate list element (not raw text, unlike append).
Key behaviors:
- If the variable does not exist, it is created as a new list containing the provided values
- Multiple values can be appended in a single call
- Qualified variable names are supported
- Variable traces (read and write) are fired appropriately
- The resulting list is returned as the command result
Note: Array element default values are not supported. If the variable indicates an element that does not exist of an array with a default value, the behavior may differ from standard Tcl.
Examples
Appending to an existing list
Output
Creating a new list
Output
Building a list in a loop
Output