I recently read Gao Qi’s Java 300 tutorial, and there was a line of code in it that Teacher Gao briefly mentioned, but upon closer inspection, I felt that I didn’t understand the knowledge points contained in it. The code is as follows:

public class Test063 { public static void main(String[] args){ Integer i = Integer.parseInt("234"); System.out.println(i); } }

In the second sentence, Interger.parseInt("234"), I checked the source code,

It is clearly stated above that the parseInt method returns a value of type int, but how can it be directly assigned to an Integer object?

I did another experiment

Integer a = 1;//报错 Integer b = Integer.parseInt("1");//编译通过

The result made me very confused. Why is this happening?

Mengxin asks for answers. Thank you!