Global Array in TCL

0
votes

I want to know how to make or create a global Array in TCL, to access it inside the Procedure. I mean, If I have a Procedure and I want to get the Array values to use it inside the Procedure, how can I do that?

1
tcl
You might benefit from reading the Tcl tutorial -- variable scope is covered in chapter 16. – glenn jackman

1 Answers

2
votes

You can use global to access the array. E.g.

array set myArr {a 1 b 2 c 3}

proc foo {} {
    global myArr
    parray myArr
}

foo
#=> myArr(a) = 1
#=> myArr(b) = 2
#=> myArr(c) = 3

Using access the global namespace using :::

proc bar {} {
    parray ::myArr
}
#=> ::myArr(a) = 1
#=> ::myArr(b) = 2
#=> ::myArr(c) = 3

You can also use upvar and uplevel, they might or might not be easier to understand depending on your experience with Tcl; they require you to understand levels (or stack frames). Basically, the global namespace is at level 0, or #0, and each time you go into a proc, you go deeper by 1 level.