java - Boolean and == vs =

Question

The language is Java. Given this:

public static void main(String[] args) {
    Boolean b1 = true;
    Boolean b2 = true;
    int i1 = 1;

    if (b1 = true) //line 5
    if (b1 == true}  // line 6

I understand that b1 == true is a equivalent test , which will give the result : true OR false. However, with b1 = true , which to my understanding is a declaration, which should return nothing but in this case : b1 = true returns true, exactly the same as == test?

Can you explain why? Thanks!

Answer 1

if (identifier = literal) evaluates to:

identifier = literal;  
if (identifier)

first you assign the literal to the identifier. then you test it post assignment