Delete object if exists

Caio shared this question 4 years ago

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I want to delete an object if it exists using IsDefined() but even using this command I get an error saying: undefined variable a ..

I'm trying this If(IsDefined(a), Delete(a)) hope someone help me please

Thanks in advance

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Comments (5)

rami ● 4 years ago

Write without any condition:

Delete(a)

nothing is happen when "a" not exist. After Delete(a) you can be sure that "a" not exist.

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Note1: IsDefined() is

- false when the object exist and the value is undefined

- true when the object exist and the value is not undefined

- go to an error if object not exist (see also exception Note2)

only in JavaScript (not in ggb-scripts) you can ask "exists(String objName)"

Note2: When a table-cell is empty (not exist)

after IsDefined(<empty-cell>) no error is happen but now the cell is not empty (the object exists) and the value of the cell is undefined, so the answer is false.

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Caio ● 4 years ago

This really worked! Was exactly what I needed thank you !!

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Diaa ● 2 years ago

It is really annoying to not have such a function check for object existence till today. Thanks for your hint on the javascript trick.

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Michael Borcherds ● 2 years ago

Try IsDefined(Object("A"))

You have to to very careful with the use of Object() though, in particular the order in the construction protocol

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Diaa ● 2 years ago

@Michael, the following should assign '1' to "d" if "AA" is defined and '0' if not,

d=If(IsDefined(Object("AA")),1,0)

However, I can't find any value assigned to "d"

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