Package cn. Itcast. Day15. Demo03; 

Import the Java. IO. FileInputStream; 
Import the Java. IO. IOException; 

Public class Demo03InputStream {
Public static void main (String [] args) throws IOException {
FileInputStream fis=new FileInputStream (" day15 p-code \ \ which xt "); 
int len=0; 
While ((len=fis. Read ())!=1) {
System. The out. Print ((char), len); 
} 
Fis. Close (); 
} 
} 

Why would a len variables, while not reinvent the wheel, cycle ((len=fis. Read ())!=1) why can't change to the while (fis) read ()!=1), I can't get the right result after changed,,,, what a great god understand to dispel doubts, thank you