Error in checking variable in while loop

Question

I am trying to check the value of a variable in a while loop

 set resultReturn 0
 while {expr $resultReturn == 0} {
    # Apply the stream configurations.
    set resultReturn [stc::apply]
 }

I am getting the following error:

syntax error in expression "expr $resultReturn == 0": variable references require preceding $

What should be the correct way to check the variable in an infinite loop until it changes value from 0?

Though given your error message, I would check resultReturn and make sure you are getting a valid numeric value back. — Brad Lanam
– Brad Lanam, Commented Nov 30, 2016 at 16:36

Brad Lanam · Accepted Answer · 2016-11-30 16:30:31Z

3

While takes a test as its first argument and processes it in the same manner as expr.

while { $resultReturn == 0 } {

References: while

answered Nov 30, 2016 at 16:30

Brad Lanam

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