Difference between revisions of "Local Variables"
m (minor tweaking) |
(rewrite) |
||
| Line 1: | Line 1: | ||
| − | Local variables are variables that exist only for the duration of the script in which they are created and can only be accessed from within that script. | + | Local variables are variables that exist only for the duration of the piece of script (for example an alias or event) in which they are created, and can only be accessed from within ''that'' piece of script - not from other anywhere else, not even from the aliases that the piece of script calls. Local variables are removed automatically when the piece of script is finished, so it is not required to /[[unset]] them. Local variables are very useful for storing short-lived data, such as loop counters and temporary results. |
| − | + | Local variables can be created with the /var command: | |
| + | var %myvar = somevalue | ||
| − | + | Note that a local variable and a global variable (created with /[[set]]) with the same name may exist; in that case, the local variable will be used in the piece of script, and the global variable will not be changed. | |
| − | You can set | + | You can set multiple variables at once: |
var %x = foo, %y = bar | var %x = foo, %y = bar | ||
| − | + | Although the '=' can be left out from the /var command in some cases, it is bad practice to do so: it can lead to weird errors in other lines. | |
| − | |||
You can use /var -s to make a variable show the result when a value is set. | You can use /var -s to make a variable show the result when a value is set. | ||
| + | |||
| + | Do not use /var to create local variables with a dynamic name (e.g. ''%x [ $+ [ %y ] ]''), there is a bug in mIRC that prevents you from doing this. | ||
== Examples == | == Examples == | ||
First, let's create an [[Aliases|alias]] that's used later on. | First, let's create an [[Aliases|alias]] that's used later on. | ||
| − | alias var_example { var -s %x foo | set -s %y bar } | + | alias var_example { var -s %x = foo | set -s %y bar } |
Now, let's play around. | Now, let's play around. | ||
Revision as of 16:50, 10 November 2005
Local variables are variables that exist only for the duration of the piece of script (for example an alias or event) in which they are created, and can only be accessed from within that piece of script - not from other anywhere else, not even from the aliases that the piece of script calls. Local variables are removed automatically when the piece of script is finished, so it is not required to /unset them. Local variables are very useful for storing short-lived data, such as loop counters and temporary results.
Local variables can be created with the /var command:
var %myvar = somevalue
Note that a local variable and a global variable (created with /set) with the same name may exist; in that case, the local variable will be used in the piece of script, and the global variable will not be changed.
You can set multiple variables at once:
var %x = foo, %y = bar
Although the '=' can be left out from the /var command in some cases, it is bad practice to do so: it can lead to weird errors in other lines.
You can use /var -s to make a variable show the result when a value is set.
Do not use /var to create local variables with a dynamic name (e.g. %x [ $+ [ %y ] ]), there is a bug in mIRC that prevents you from doing this.
Examples
First, let's create an alias that's used later on.
alias var_example { var -s %x = foo | set -s %y bar }
Now, let's play around.
; set values to variables with set so values exists until they're unset set %x 10 set %y %x ; value from %x is copied to %y ; call of your own alias var_example ; displays ; * Set %x to foo ; * Set %y to bar ; now, let's display %x and %y values echo -a %x ; returns 10 echo -a %y ; returns bar
As we can see, %x still holds its original value because /var only creates a local variable, but %y was overwritten with /set.
| Contributed by Tovrleaf |
