Description: Increment the value of a variable
Syntax: incr varName ?increment?
Argument: variable, increment amount (default is 1)
Returns: value of variable plus increment
See Also: variable
Increments the value of variable 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 in variable varName and also returned as result.