What is the difference between "+=" & "=+"

Answer 1

x+=1 is a increment operator like x++
x=+1 isn't exist

Answer 2

The first is an accumulator operator the second doesn't exist, if you'd use it anywhere I'm your code you'd get a syntax error

Answer 3

second doesn't exist..
first one will add the amount of value (which is written after =) to the present value of the variable..
e.g. a+=2 ~ a=a+2