Update chapter_3_2.md

src/chapter_3/chapter_3_2.md

@@ -167,7 +167,7 @@ fn main() {
 fn main() {
     let a = [1, 2, 3, 4, 5];           //直接写数组的值
     let b: [i32; 5] = [1, 2, 3, 4, 5]; //显示指定数组的类型和长度
-    let c: [i32; 5] = [3; 5];          //数组每个元素为同样的值，等价于let a = [5, 5, 5, 5, 5];
+    let c: [i32; 5] = [3; 5];          //数组每个元素为同样的值，等价于let a = [3, 3, 3, 3, 3];
 }
 ```