---
name: "join"
section: "n"
platform: "linux"
package: "tcl"
version: "8.6.16-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/join/n"
---

# join(n)

Create a string by joining together list elements

```

```

## NAME

join - Create a string by joining together list elements

## SYNOPSIS

**join** *list* ?*joinString*?

```

```

## DESCRIPTION

The *list* argument must be a valid Tcl list. This command returns the string formed by joining all of the elements of *list* together with *joinString* separating each adjacent pair of elements. The *joinString* argument defaults to a space character.

## EXAMPLES

Making a comma-separated list:

```
set data {1 2 3 4 5}
join $data ", "
     → 1, 2, 3, 4, 5
```

Using **join** to flatten a list by a single level:

```
set data {1 {2 3} 4 {5 {6 7} 8}}
join $data
     → 1 2 3 4 5 {6 7} 8
```

## SEE ALSO

[list(n)](/list/n.md), [lappend(n)](/lappend/n.md), [split(n)](/split/n.md)

## KEYWORDS

element, join, list, separator