diff --git a/docs/chapter_computational_complexity/time_complexity.md b/docs/chapter_computational_complexity/time_complexity.md
index 8ef61d06..5a44a17f 100644
--- a/docs/chapter_computational_complexity/time_complexity.md
+++ b/docs/chapter_computational_complexity/time_complexity.md
@@ -1013,7 +1013,7 @@ $$
 
     ```typescript title="time_complexity.ts"
     /* 线性阶（遍历数组） */
-    function arrayTraversal(nums: number[]) {
+    function arrayTraversal(nums: number[]): number {
         let count = 0;
         // 循环次数与数组长度成正比
         for (let i = 0; i < nums.length; i++) {