javascript/memoization.html at master · sanasham/javascript · GitHub

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<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Memoizatioin</title>
  </head>
  <body>
    <h1>Memoizatioin</h1>
    <input type="text" name="" id="calNumber" />
    <button type="button" onclick="effective()">calculate</button>

    <script>
      let sum = 0;
      let calculatedSum = (n) => {
        for (let i = 0; i < n; i++) {
          sum += i;
        }
        return sum;
      };
      const memoizedSum = (clb) => {
        console.time();
        let cache = {};
        console.log('cache', cache);
        return function () {
          let n = document.getElementById('calNumber').value;
          console.log('n value', n);
          if (n in cache) {
            console.log('from cache');
            return cache[n];
          } else {
            console.log('first time');
            let result = clb(n);
            cache[n] = result;
            console.log('cache', cache);

            return result;
          }
        };
      };
      //console.time();
      const effective = memoizedSum(calculatedSum);

      console.log(effective(2));
      // console.timeEnd();
    </script>
  </body>
</html>