diff --git a/problems/0347.前K个高频元素.md b/problems/0347.前K个高频元素.md
index 8a219c6a..cca9b0ed 100644
--- a/problems/0347.前K个高频元素.md
+++ b/problems/0347.前K个高频元素.md
@@ -421,7 +421,7 @@ class Heap {
         let left = 1; // left 是左子节点下标 left + 1 则是右子节点下标
         let searchChild = this.compare(left, left + 1) > 0 ? left + 1 : left;
 
-        while (searchChild !== undefined && this.compare(index, searchChild) > 0) { // 注意compare参数顺序
+        while (this.compare(index, searchChild) > 0) { // 注意compare参数顺序
             [this.queue[index], this.queue[searchChild]] = [this.queue[searchChild], this.queue[index]];
 
             // 更新下标