Javascript expressions

Question

Hi could someone help me understand the logic here. If this question is not within guidelines i will gladly remove it. It is from the challenge questions.

So here goes
Var a = 1;
Var b = 2;
Var d = "8";
Var c = d+(a= b+1)-d;
Alert(c);

Output
75

Please explain the formula here var c.

Answer 1

Thank you!!!

Answer 2

first the value in bracket is evaluated ,a=3,
expression is now left as d+a-d (I am assuming that's how it works as I haven't seen assigning in between an expression)

"8"+3-"8" is reduced to "83"-"8" due to concatenation and conversion of 3 to string ,which results in 75 as JavaScript will implicitly convert 83 and 8 to integer