Could any one can explain what is the meaning of the line .... "total+=x"

Answer 1

total+=x is same as adding value of x in total and then storing the final value in total variable i.e total = total + x;

Answer 2

total+=x; is shortened form of
total =total+x;

Answer 3

Those are called Assignment Operators.

a += b is equivalent to a = a + b
a -= b is equivalent to a = a - b
a *= b is equivalent to a = a * b
a /= b is equivalent to a = a / b

Answer 4

in that line first which operation is going to operate ?

Answer 5

+= according to bodmas ?

Answer 6

tq