Question

I cant seem to fine what the operator sign " += " stands for?

Answer 1

+= is an assignment operator

It's used as a shorthand in the following type of statement. Instead of writing,

a = a +1 (i.e. incrementing the variable by 1)

one can write the above in shorthand as:

a+=1 (i.e. increment the value of a by and assign that to a)

Answer 2

Thank you,

Answer 3

Also, you can use it with basically any other operation, i.e., a/=2 is equivalent to a = a/2, a *= 2, is a = a*2 etc.

Answer 4

That is very use full information. It helps to shorten the code.

Answer 5

One thing I have done in the past is go to Amazon.com and look at their python books and when they say look inside is look through the index section and many times syntax will show up that way and give a brief description.

Answer 6

This kind of assignment exists in most languages nowadays (java, c, javascript, ...) but you should be warned that it may make your code less readable, especially if you're a new programmer. Don't sacrifice readibility to syntactic sugar !

Answer 7

yes it is, i think this operator is basically from c, then use by the next generation programming language like java, php, and so on. like in java we can use ".=" to concate two words or two variable

Answer 8

actually shorthands might make code more readible, because if you use long variable names which explain purpose of variable then it may take a lot of space to write and your eyes need to go from left to right too much

Answer 9

I agree with you that it helps when you're already experimented. But when someone starts to program, I don't recommend it. It's probably a matter of taste, so try it if you want, and see what's the more readable for you.

Answer 10

owh ok, thanks for your recommendation :)

Answer 11

I must say that I find the ++ notation a lot cuter than += but, alas, I am not the BDFL :-)

Answer 12

actually if you use ++ , usually use at while loop, or for loop

Answer 13

Yeah, I know. I was just saying that I think ++ a lot cuter than += 1, that I find rather ugly for a shorthand.

Answer 14

Also, in the C family of languages, the unary pre/suffix increment/decrement (as well as the compound assignment operators) is a valid expression, whereas in Python the compound assignment operators (+= etc.) must be at the top level of a statement.

In C:
A[i += 1] = 4; // Alright

in Python:
A[i += 1] = 4 # BZZT!! SYNTAX ERROR!!!

Answer 15

http://docs.python.org/reference/simple_stmts.html#augmented-assignment-statements

Answer 16

@bmp, the coding style is depend on the person :)

Answer 17

but in python you can't use ++, can you?

Answer 18

i don't know tomas, try to ask another one here, i don't program in phyton yet

Answer 19

it was kinda rhetorical question, because it doesn't allow me to use ++

Answer 20

owh, ok. thanks for sharing