diff --git a/javascript/1358-number-of-substrings-containing-all-three-characters.js b/javascript/1358-number-of-substrings-containing-all-three-characters.js
new file mode 100644
index 000000000..12ccdb657
--- /dev/null
+++ b/javascript/1358-number-of-substrings-containing-all-three-characters.js
@@ -0,0 +1,35 @@
+/**
+ * Sliding Window
+ * Time O(n) | Space O(1)
+ * https://leetcode.com/problems/number-of-substrings-containing-all-three-characters
+ * @param {string} s
+ * @return {number}
+ */
+var numberOfSubstrings = function(s) {
+    
+    let left = 0;
+    let right = 0;
+    let aCount = 0;
+    let bCount = 0;
+    let cCount = 0;
+    let total = 0;
+
+    while (right < s.length) {
+
+        if (s[right] === "a") aCount++;
+        if (s[right] === "b") bCount++;
+        if (s[right] === "c") cCount++;
+
+        while (aCount && bCount && cCount) {
+            total += s.length - right;
+            if (s[left] === "a") aCount--;
+            if (s[left] === "b") bCount--;
+            if (s[left] === "c") cCount--;
+            left++;
+        }
+
+        right++;
+    }
+
+    return total;
+};