Change kotlin val in debugger

Question

How change val property (not method variable) in debugger?

Yes, I know that val is final analog

Breakpoint here:

Set value disabled in context menu:

Evaluate not work:

Then you should know you can't change a final, assigned value unless you somehow [hack something together with reflection](https://stackoverflow.com/questions/3301635/change-private-static-final-field-using-java-reflection). It's final for a reason — Zoe, Apr 12 '19 at 14:55

Simulant · Answer 1 · 2019-04-12T15:04:26.980

6

In the debugger select the value use the context menue on right click to select "set Value..." (default shortcut F2). The value of the variable should now be displayed in a text field. Enter the desired value and press enter to change the value. You only need to enter the value not an assignment (e.g. x = "test" is wrong, just enter the value "test"). The changed value is now applied to the field.

In the debugger it IS also possible to change values on immutable val defined values in Kotlin as it is also possible to change the value on final defined variables in Java.

edited Apr 12 '19 at 15:04

answered Apr 12 '19 at 14:59

Simulant

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thanks, but this not work with `val` property. I update question – Nick May 22 '19 at 19:04
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No it is not possible for val – Le_Enot Nov 18 '19 at 12:26

score 2 · Answer 2 · answered Nov 18 '19 at 12:35

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You can do it using reflection.
Just open the Evaluate Expression menu, then type:
val field = Main::class.java.getDeclaredField("b")
field.isAccessible = true
field.set(b, true)

answered Nov 18 '19 at 12:35

Le_Enot

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score 2 · Answer 3 · answered Feb 13 '20 at 17:36

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I was able to modify val value on the fly using "evaluate and log". Check full answer

answered Feb 13 '20 at 17:36

Islam Salah

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Change kotlin val in debugger

3 Answers3