an error handling operation for checking of an array access in program code is modified during compilation thereof . a sequentially arranged null checking operation and array bounds checking operation for the array access are located . the array bounds checking operation has a corresponding error handling operation operable for setting an array bounds error . the located sequentially arranged null checking operation is removed . the corresponding error handling operation for the located sequentially arranged array bounds checking operation is modified to perform the removed null checking operation during execution of the program code .