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

```

```

# [NAME](#NAME)

append - Append to variable

# [SYNOPSIS](#SYNOPSIS)

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

```

```

# [DESCRIPTION](#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. If *varName* indicate an element that does not exist of an array that has a default value set, the concatenation of the default value and all the *value* arguments will be stored in the array element. 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, “**append a $b**” is much more efficient than “**set a $a$b**” if **$a** is long.

# [EXAMPLE](#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](#SEE_ALSO)

[concat(n)](/man/os/tcl/concat.n), [lappend(n)](/man/os/tcl/lappend.n)

# [KEYWORDS](#KEYWORDS)

append, variable

Tcl

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Document: append(n) from tcl 9.1.0-r0 (Chainguard OS)
Source: https://downloads.sourceforge.net/project/tcl/Tcl/9.1.0/tcl9.1.0-src.tar.gz