One implementation could be:

(function(w) {
  const timeoutIds = [];

  // store the original method
  const originalTimeoutFn = w.setTimeout;

  // override the original setTimeout method with our
  // custom implementation
  w.setTimeout = function(fn, delay) { 
    const id = originalTimeoutFn(fn, delay);
    timeoutIds.push(id);
    
    //return the id so that it can be originally cleared
    return id;
  }

  w.clearAllTimeout = function(){
    //clear all timeouts
    while(timeoutIds.length){
      clearTimeout(timeoutIds.pop());
    }
  }
})(window);

Test it out using:

Case 1 without clearing

setTimeout(() =&gt; {console.log("One")}, 4000);
setTimeout(() =&gt; {console.log("Two")}, 5000);
setTimeout(() =&gt; {console.log("Three")}, 6000);
setTimeout(() =&gt; {console.log("Four")}, 7000);


// prints
// One
// Two
// Three
// Four

Case 2 with clearing

setTimeout(() =&gt; {console.log("One")}, 4000);
setTimeout(() =&gt; {console.log("Two")}, 5000);
setTimeout(() =&gt; {console.log("Three")}, 6000);
setTimeout(() =&gt; {console.log("Four")}, 7000);


clearAllTimeout();
// prints nothing

Do you see value in our efforts?

Implement clearAllTimeout in JavaScript | Facebook Interview Question

@Yomesh Gupta