18 - Adding Up Times with Reduce

Adding Up Times With Reduce

An ul representing a playlist where each li represents a video and it has a data-time attribute with its duration(string). Calculate the total time in hours:minutes:seconds

Notes:

• Two implementations, one is self-describing the other is serious stuff 😝

      const timeAttributes = Array.from(document.querySelectorAll('[data-time]'));
  
      const totalSeconds = timeAttributes
          .map(node => node.dataset.time)
          .map(timeCode => {
          const [mins, secs] = timeCode.split(':').map(parseFloat);
          return mins * 60 + secs;
          })
          .reduce((a, b) => a + b);

      const timeAttributes = Array.from(document.querySelectorAll('[data-time]'));
  
      const totalSeconds = timeAttributes
          .reduce((a, b) => {
              b = b.dataset.time.split(':').map(parseFloat);
              return a + b[0]*60 + b[1];
          }, 0);

• There is also a function that converts from seconds to a hours:minutes:seconds format.