Angular (NG): Snippet to display a count down in seconds

component.html

Time Left: {{countDownSecondsLeft}}

component.ts

     // @todo: Somewhere in your code, start the count down by doing: _countDownInit(() => { /* code to be executed on countdown complete */ })
      
     // region countdown
     private readonly COUNT_DOWN_SECS = 3;
     private _countDownId: any;
     countDownSecondsLeft = this.COUNT_DOWN_SECS;

     private _countDownClear() {
          clearInterval(this._countDownId);
          this._countDownId = null;
     }
     private _countDownInit(cb: () => void) {
          this._countDownClear();
          this.countDownSecondsLeft = this.COUNT_DOWN_SECS;
          this._countDownId = setInterval(() => cb(), 1000);
     }
     private _countDownTick() {
          const v = --this.countDownSecondsLeft;
          if (v === 0) {
               this.confirm();
          }
     }
     // endregion