string to integer

[Driber]

can someone please post an example of how to convert a string to an integer

[nml375]

That would depend on the string in question.. think you could give a couple of examples?
In most cases, scan would be your friend however.

A simple example:

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set string "There are 2 users"
set int [scan $string "There are %d users"

[Driber]

that's not what I'm looking for

ok here is an example:

I have $str which contains " 4" (that's a whitespace and a number four)

I need that string to be converted to an integer so that I can calculate with it
for example:

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incr str 1

to make it 5


the php equivalent to this would be:

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<?php
$str = " 4";
$num = (int)$str;
?>

[nml375]

In this case you might be able to use the expr command. Be aware though that this command may cause some serious security issues if data is not properly sanitized, as all data will be passed through the tcl interpreter.

Of course, scan would still be an option, with a proper pattern...

A third option might be to simply strip the string of spaces using string trim, as tcl will do the necessary type-casting provided the data makes sense (i.e. string looks like an integer if it only contains digits, as a float if it only contains digits and a single dot, and so on).

[Driber]

I didn't know tcl automatically does type-casting on variables, so I will give string trim a try

thanks