bionic (3) incr.3tcl.gz

NAME

       incr - Increment the value of a variable

SYNOPSIS

       incr varName ?increment?
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DESCRIPTION

       Increments  the value stored in the variable whose name is varName.  The value of the variable must be an
       integer.  If increment is supplied then its value (which must be an integer) is added  to  the  value  of
       variable  varName;   otherwise  1  is  added  to varName.  The new value is stored as a decimal string in
       variable varName and also returned as result.

       Starting with the Tcl 8.5 release, the variable varName passed to incr may be unset, and in that case, it │
       will be set to the value increment or to the default increment value of 1.

EXAMPLES

       Add one to the contents of the variable x:
              incr x

       Add 42 to the contents of the variable x:
              incr x 42

       Add the contents of the variable y to the contents of the variable x:
              incr x $y

       Add  nothing  at  all  to the variable x (often useful for checking whether an argument to a procedure is
       actually integral and generating an error if it is not):
              incr x 0

SEE ALSO

       expr(3tcl)

KEYWORDS

       add, increment, variable, value