Using the 'del' command is the most known and easiest method to delete variables in Python. The del keyword deletes the objects. Since everything in Python is an object, therefore lists, tuples and dictionaries can also be deleted using 'del'.
The Clear-Variable cmdlet deletes the data stored in a variable, but it does not delete the variable. As a result, the value of the variable is NULL (empty). If the variable has a specified data or object type, this cmdlet preserves the type of the object stored in the variable.
Variables can be deleted from within the Calculator application via the DelVar command (press [MENU]→Actions→Delete Variable).
After charging the battery, press c to turn on the handheld. A progress bar is displayed while the operating system loads. Next, choose preferences for language and font size when prompted. Note: To turn the handheld off, press / c.
From the home screen scroll over to Scratchpad and highlight A Calculate or just press the A key. You can also get to the Scratchpad by pressing » . To clear the Scratchpad press b then 1:Actions then 5:Clear History. To clear the Scratchpad and all its variables, press ~ then choose option B: Clear Scratchpad.
Clear: The C button erases the last number or operation entered, use it if the last number you entered was a mistake.
To delete a variable, use the D line command. However, to avoid conflict with the I (insert) line command, the Variables option does not allow you to type a number along with the D command to delete more than one line simultaneously.
Deleting variables created in Q
Variables that have been created in Q will have their variable name shown in the Variables and Questions tab in a black font. If the variables have been created in Q, just select them in the Variables and Questions tab, right-click and select Delete Copied or Constructed Variable(s).
Removing text from a Text variable
For example, if your variable was called Vcust1, and it contained commas that you wished to remove, you would write the expression: (Vcust1). replace(/,/g,"").
No, you can't "undeclare" a variable. It is 'undeclared' when it goes out of scope. Note that variable declaration is only relevant during compilation. Once the program has been compiled, variables are no longer 'declared' or 'undeclared'.