(The Java class is available for this but the routine here is used as an example.) A prime number is any number that can be divided by itself and the number one, so the sequence begins 2, 3, 5, 7, 11, 13, 17, 19, 23, etc. Routines to perform a primality test are well established and are usually based upon the Sieve of Eratosthenes. Likewise for small prime numbers, such as the eggshell number 77345993. Well if that number is typed into an old desktop calculator with a Liquid Crystal Display (LCD) and the calculator is turned upside down, then it sort of reads EGGSHELL.
This function was derived from the script at Prime Curios! For most numbers the routine executes extremely quickly, however, a long integer can have up to 19 digits. Now try a really big prime number, a web search will reveal plenty, how about nineteen ones: .
This id can be used in the activity source file to perform any action on the component. It includes a lot of static nested classes such as menu, id, layout, attr, drawable, string etc.
is not working as intended, or you UI is sluggish, then read on.
If no feedback is given for a few seconds users can become annoyed.
This call posts a message to update the display, so the update does not happen immediately.Once remaining app code has run the UI messages are processed. A running app's execution thread can be viewed as shown in this simplified diagram.What this means is that changes to the UI can get delayed, and in some cases not appear to occur, when the running app code is doing a time intensive tasks.If a 19 digit number is a prime then the inner loop can run several million times and a long pause in the program occurs. package com.example.isprime; import android.support.v7 The result is that the UI gets the chance to update whilst the code that was previously blocking the update still executes (after being kicked off by the timer).
A straightforward solution for when a quick UI update is required when code can potentially hog the main thread for a short while.
Whenever a section of code is going to take some time to execute, maybe a second or more, then the use of Async Task is recommended.