Add implementation for Jump Search in JS

JavaScript/jumpSearch.js

@@ -0,0 +1,36 @@
+function jumpSearch(arr, x, n) {
+    // Finding block size to be jumped
+    let step = Math.sqrt(n);
+
+    // Finding the block where element is present
+    let prev = 0;
+    while (arr[Math.min(step, n) - 1] < x) {
+        prev = step;
+        step += Math.sqrt(n);
+        if (prev >= n) {
+            return -1;
+        } 
+    }
+
+    // Doing a linear search for x in 
+    // block beginning with prev
+
+    while (arr[prev] < x) {
+        prev += 1;
+        if (prev == Math.min(step, n)) {
+            return -1;
+        }
+    }
+
+    if (arr[prev] == x) {
+        return prev;
+    }
+    return -1;
+}
+
+let arr = [ 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610 ];
+let x = 55;
+let n = arr.length;
+
+let index = jumpSearch(arr, x, n);
+console.log(`Number ${x} is at index ${index}`);