factorial.js

amit265 · amit265 · commit 0b1aaf118f67 · 2026-01-27T00:06:32.000+05:30
diff --git a/javascript/3_math-programs/factorial.js b/javascript/3_math-programs/factorial.js
@@ -0,0 +1,63 @@
+// 5. Factorial of a Number
+
+function factorial(n) {
+  let fact = 1;
+  if (n === 0) return 1;
+  if (n === 1) return 1;
+
+  for (let i = 2; i <= n; i++) {
+    fact *= i;
+  }
+
+  return fact;
+}
+
+console.log(factorial(3));
+console.log(factorial(1));
+
+// using recursio
+
+function factorials(n) {
+  if (n === 0 || n === 1) return 1;
+  return n * factorials(n - 1);
+}
+
+console.log(factorials(5));
+console.log(factorials(10));
+console.log(factorials(0));
+console.log(factorials(1));
+console.log(factorials(3));
+console.log(factorials(4));
+
+// using while looop
+
+function factorialWhile(n) {
+  let res = 1;
+
+  while (n > 1) {
+    res *= n;
+    n--;
+  }
+  return res;
+}
+
+console.log(factorialWhile(1));
+console.log(factorialWhile(2));
+console.log(factorialWhile(3));
+console.log(factorialWhile(105));
+
+// using memoization
+
+function factorialUsingMemo(n) {
+  const cache = {};
+  if (n === 0 || n === 1) {
+    return 1;
+  }
+  if (cache[n]) {
+    console.log("value from caeche");
+    return cache[n];
+  }
+  cache[n] = n * factorialUsingMemo(n - 1);
+  return cache[n];
+}
+console.log(factorialUsingMemo(105));
