diff --git a/java/0205_isomorphic_strings b/java/0205_isomorphic_strings.java
similarity index 100%
rename from java/0205_isomorphic_strings
rename to java/0205_isomorphic_strings.java
diff --git a/javascript/1941-check-if-all-characters-have-equal-number-of-occurrences.js b/javascript/1941-check-if-all-characters-have-equal-number-of-occurrences.js
new file mode 100644
index 000000000..320ef89ea
--- /dev/null
+++ b/javascript/1941-check-if-all-characters-have-equal-number-of-occurrences.js
@@ -0,0 +1,23 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+var areOccurrencesEqual = function (s) {
+    let arr = []
+    for (i = 0; i < s.length; i++) {
+        let count = 0;
+        for (j = 0; j < s.length; j++) {
+            if (s[i] == s[j]) {
+                if (i > j) {
+                    break;
+                }
+                count++
+            }
+        }
+        if (count != 0) {
+            arr.push(count)
+        }
+    }
+    let set = new Set(arr)
+    return set.size == 1
+};
\ No newline at end of file
diff --git a/javascript/2626-array-reduce-transformation.js b/javascript/2626-array-reduce-transformation.js
new file mode 100644
index 000000000..1bb5b9d92
--- /dev/null
+++ b/javascript/2626-array-reduce-transformation.js
@@ -0,0 +1,22 @@
+/**
+ * @param {number[]} nums
+ * @param {Function} fn
+ * @param {number} init
+ * @return {number}
+ */
+var reduce = function (nums, fn, init) {
+    var val = init;
+    for (let i = 0; i < nums.length; i++) {
+        val = fn(val, nums[i])
+    }
+    return val;
+};
+
+
+var reduce = function (nums, fn, init) {
+
+    for (let i = 0; i < nums.length; i++) {
+        init = fn(init, nums[i])
+    }
+    return init
+};
\ No newline at end of file
diff --git a/javascript/2629-function-composition.js b/javascript/2629-function-composition.js
new file mode 100644
index 000000000..2e1a679f2
--- /dev/null
+++ b/javascript/2629-function-composition.js
@@ -0,0 +1,22 @@
+/**
+ * @param {Function[]} functions
+ * @return {Function}
+ */
+var compose = function (functions) {
+    return function (x) {
+        if (functions.length === 0) {
+            return x;
+        }
+        var result = x;
+        for (var i = functions.length - 1; i >= 0; i--) {
+            result = functions[i](result);
+        }
+
+        return result;
+    }
+};
+
+/**
+ * const fn = compose([x => x + 1, x => 2 * x])
+ * fn(4) // 9
+ */
\ No newline at end of file
diff --git a/javascript/2634-filter-elements-from-array.js b/javascript/2634-filter-elements-from-array.js
new file mode 100644
index 000000000..8d9d3de5d
--- /dev/null
+++ b/javascript/2634-filter-elements-from-array.js
@@ -0,0 +1,9 @@
+/**
+ * @param {number[]} arr
+ * @param {Function} fn
+ * @return {number[]}
+ */
+var filter = function (arr, fn) {
+    const result = arr.filter(fn)
+    return result
+};
\ No newline at end of file
diff --git a/javascript/2635-apply-transform-over-each-element-in-array.js b/javascript/2635-apply-transform-over-each-element-in-array.js
new file mode 100644
index 000000000..65b435771
--- /dev/null
+++ b/javascript/2635-apply-transform-over-each-element-in-array.js
@@ -0,0 +1,8 @@
+/**
+ * @param {number[]} arr
+ * @param {Function} fn
+ * @return {number[]}
+ */
+var map = function (arr, fn) {
+    return arr.map((element, index) => fn(element, index));
+};
\ No newline at end of file
diff --git a/javascript/2703-return-length-of-arguments-passed.js b/javascript/2703-return-length-of-arguments-passed.js
new file mode 100644
index 000000000..c7f18af22
--- /dev/null
+++ b/javascript/2703-return-length-of-arguments-passed.js
@@ -0,0 +1,11 @@
+/**
+ * @param {...(null|boolean|number|string|Array|Object)} args
+ * @return {number}
+ */
+var argumentsLength = function (...args) {
+    return args.length;
+};
+
+/**
+ * argumentsLength(1, 2, 3); // 3
+ */
\ No newline at end of file
diff --git a/javascript/2704-to-be-or-not-to-be.js b/javascript/2704-to-be-or-not-to-be.js
new file mode 100644
index 000000000..2f718b897
--- /dev/null
+++ b/javascript/2704-to-be-or-not-to-be.js
@@ -0,0 +1,21 @@
+/**
+ * @param {string} val
+ * @return {Object}
+ */
+var expect = function (val) {
+    return {
+        toBe: (val2) => {
+            if (val !== val2) throw new Error("Not Equal");
+            else return true;
+        },
+        notToBe: (val2) => {
+            if (val === val2) throw new Error("Equal");
+            else return true;
+        }
+    }
+};
+
+/**
+ * expect(5).toBe(5); // true
+ * expect(5).notToBe(5); // throws "Equal"
+ */
\ No newline at end of file