---
name: "append"
section: "n"
platform: "macos"
package: "tcl"
version: "152"
release: "macOS 26.5"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/append/n"
---

# append(n)

Append to variable

## NAME

append - Append to variable

## SYNOPSIS

**append** *varName* ?*value value value ...*?

## DESCRIPTION

Append all of the *value* arguments to the current value of variable *varName*.  If *varName* does not exist, it is given a value equal to the concatenation of all the *value* arguments. The result of this command is the new value stored in variable *varName*. This command provides an efficient way to build up long variables incrementally. For example, is much more efficient than if **$a** is long.

## EXAMPLE

Building a string of comma-separated numbers piecemeal using a loop. set var 0 for {set i 1} {$i\<=10} {incr i} {\
    **append** var "," $i } puts $var # Prints 0,1,2,3,4,5,6,7,8,9,10

## SEE ALSO

[concat(n)](/concat/n.md), [lappend(n)](/lappend/n.md)

## KEYWORDS

append, variable