Run code only once [duplicate]

Question

I cant figure out how to run a part of code in ViewDidLoad() method only once. I don't want that part of the code to be executed until the app is started again. Thanks for any help!

Answer 1

You can use dispatch_once in your viewDidLoad:

static dispatch_once_t once;
dispatch_once(&once, ^
{
    // Code to run once
});

This will make the code run only once until you exit and close your app.

Answer 2

You can also set up a BOOL flag to check whether the code has executed.

set up the bool above the implementation in the .m file:

static BOOL codeExecuted = NO;

in the -viewDidLoad() method:

if (!codeExecuted)
{

    //run code
    codeExecuted = YES;

}