diff --git a/src/leecode/javascript/303.区域和检索 - 数组不可变.js b/src/leecode/javascript/303.区域和检索 - 数组不可变.js
new file mode 100644
index 0000000..f651437
--- /dev/null
+++ b/src/leecode/javascript/303.区域和检索 - 数组不可变.js	
@@ -0,0 +1,46 @@
+/*
+ * @lc app=leetcode.cn id=303 lang=javascript
+ * @lcpr version=
+ *
+ * [303] 区域和检索 - 数组不可变
+ */
+
+// @lc code=start
+/**
+ * @param {number[]} nums
+ */
+var NumArray = function(nums) {
+  this.table = nums;
+};
+
+/** 
+ * @param {number} left 
+ * @param {number} right
+ * @return {number}
+ */
+NumArray.prototype.sumRange = function(left, right) {
+    let ret = 0;
+    for (let i = left; i <= right; i ++) {
+      ret += this.table[i];
+    }
+    return ret;
+};
+
+var x = new NumArray([1,2,3,4]);
+console.log(x.sumRange(1,2));
+/** 
+ * Your NumArray object will be instantiated and called as such:
+ * var obj = new NumArray(nums)
+ * var param_1 = obj.sumRange(left,right)
+ */
+// @lc code=end
+
+
+
+/*
+// @lcpr case=start
+// ["NumArray","sumRange","sumRange","sumRange"]\n[[[-2,0,3,-5,2,-1]],[0,2],[2,5],[0,5]]\n
+// @lcpr case=end
+
+ */
+