The Lock Command


Command Summary

Locks the specified variables

Command Syntax

Lock var1, var2, etc

Menu Location

This command can't be found in any menu besides the command catalog.

Calculator Compatibility

This command works on all calculators.

Token Size

X byte(s)

The lock command prevents a variable's value from changing. In programs and functions, lock is usually used to stop a variable from undesirably changing. If a variable is universally defined (like files in folders), the lock command has a popular purpose of making the variable constant (unchanging) throughout use in sets of programs.

input "Input var1 here: ",var1
lock var1
text "You can no longer change var1."
© var1 can now be used as a constant variable.
©... <program statements that require the value of var1>
prgm2() ©var1 may not change in any other programs.
unlock var1

Note: the © command will turn any code written until the next ':' into comments. (neat-freaks love this.)
Comments are very helpful for people who forget, especially when dealing with tricky commands and code. Using comments for the lock command will help you remember to unlock the variable when the time comes to delete it.

Related Commands

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