Quoting:
"A null pointer exception is like having the address to a house that was never built. It means a programmer has referred to an object that doesn’t actually exist because it was never described in the code. Null pointers are extremely common and relatively easy to fix—easy enough to be boring, in fact.
Unfortunately, the tedious work of finding and fixing errors like these still takes up much of a developer’s time and mental energy. A 2016 evaluation of 1,000 Android apps [PDF] found that null pointers caused more crashes than any other kind of error, including illegal arguments, array index out of bounds exceptions, and bad tokens.
(...)
"Facebook’s developers make more than 100,000 commits every week, and the Facebook app for Android contains millions of lines of code. Sapienz runs hundreds of emulators around the clock to review code before and after it’s shipped, conducting tens of thousands of tests every day. "
