TypeError: Cannot read properties of undefined (reading 'ma…
Error message
TypeError: Cannot read properties of undefined (reading 'map')
What broke
The code attempted to use the 'map' method on a variable that is currently undefined. This usually happens when the variable is expected to be an array but hasn't been initialized or assigned a value.
Why it broke
It broke because the variable you are trying to access is not defined at the time of the call. This can happen if the variable is not properly initialized or if the data fetching process failed, leaving the variable undefined.
How to fix
To fix this, ensure that the variable is initialized as an array before calling 'map'. You can also add a check to confirm that the variable is defined and is an array before using 'map'.
Code fix
const myArray = myVariable || []; myArray.map(item => item.property);Explained by ErrorOracle
Prevention tip
You can also add a check to confirm that the variable is defined and is an array before using 'map'.
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