diff --git a/Data Structures/stack.js b/Data Structures/stack.js
new file mode 100644
index 0000000..188bd1c
--- /dev/null
+++ b/Data Structures/stack.js	
@@ -0,0 +1,5 @@
+// https://www.freecodecamp.org/learn/coding-interview-prep/data-structures/learn-how-a-stack-works
+var homeworkStack = ["BIO12", "HIS80", "MAT122", "PSY44"];
+// Only change code below this line
+homeworkStack.pop();
+homeworkStack.push("CS50");