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JavaScript Callback Functions in JavaScript Callbacks with Timers Using Anonymous Functions with setInterval

Another Approach using IIFE

Andrew Chalkley : You mentioned that anonymous functions are not suitable for our clock application but how about using IIFE? It seems to work perfectly fine.

// Render time to screen (IIFE)
(() => {
  // Immediately displays time
  clockSection.textContent = getTime();
  // Updates clock at intervals of 1 second
  setInterval( () => {
    clockSection.textContent = getTime();
  }, 1000);
})();

1 Answer

Steven Parker
Steven Parker
215,372 Points

The IIFE isn't necessary, you can just do this:

// immediately display time
clockSection.textContent = getTime();
// then update clock at intervals of 1 second
setInterval( () => {
    clockSection.textContent = getTime();
  }, 1000);

But the issue (with or without IIFE) is that we violate the "DRY" principle by replicating the code that used to be in the "tickClock" function. In this particular case, it's only one line so the replication isn't a big deal; but in a more complex application it might be.