The findIndex() method returns the index of the first record in the grid that satisfies the provided testing function. Otherwise -1 is returned.
- Callback function that receives the following arguments:
- Record object with properties for each field in the grid
- Index - the zero-based index of the current grid record being processed
- Records array - array representing all of the grid records
The function must return true when the test condition is met.
Zero-based index of the found record or -1.