What does ":=" mean in Pseudocode?

Question

Really basic syntax question in pseudocode. What does := mean in Pseudocode?
Example

a := 1

I just want to know what ":=" operator does and how it is different from just "=" — ElectronAnt, Apr 21 '12 at 21:41
@Aneem *Try using it*. What happens? It is not valid in Python, but some *other* languages use `:=` for the assignment operator. — , Apr 21 '12 at 21:41
That's a Pascal assignment. Did you get the wrong language. Show some more code. — David Heffernan, Apr 21 '12 at 21:42
sorry! it's not python, it was using coding from this page: http://en.wikipedia.org/wiki/Modular_exponentiation — ElectronAnt, Apr 21 '12 at 21:44
Can we delete this post? It is misleading, once again, very sorry. — ElectronAnt, Apr 21 '12 at 21:45
Instead of deleting, why not just change your question to be about pseudocode instead of Python? I will remove my downvote, for one — David Robinson, Apr 21 '12 at 21:45
Haha @DavidHeffernan, what I mean is that pseudocode does have a StackOverflow tag. — David Robinson, Apr 21 '12 at 21:47
Voting to close as i doubt this question will have value to anyone in the future. I was going to remove the Python tag, except it specifically says Python on the title. — Steven Rumbalski, Apr 21 '12 at 21:50
See - http://programmers.stackexchange.com/questions/101716/in-pseudo-code-what-does-mean — ChrisF, Apr 22 '12 at 12:21

Tim Pietzcker · Accepted Answer · 2012-04-21T21:57:26.063

29

Pseudocode examples on Wikipedia usually use := as the assignment operator, like Pascal does (I haven't found any counterexamples yet).

You can't use it in Python directly as it would be a SyntaxError:

>>> a := 1
  File "<stdin>", line 1
    a := 1
      ^
SyntaxError: invalid syntax

Use

a = 1

instead.

edited Apr 21 '12 at 21:57

answered Apr 21 '12 at 21:42

Tim Pietzcker

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The question could get deleted though..... You might lose the rep but I think you'll keep the badge! ;-) – David Heffernan Apr 21 '12 at 21:59
@DavidHeffernan: I think if that happens I do get to keep the badge, but I don't get another one when my next answer reaches 10 upvotes... – Tim Pietzcker Apr 21 '12 at 22:12
1

I hate to star negatively-voted questions, but I just had to do this after seeing your answer. – BoltClock Apr 22 '12 at 12:13
Wow, we even have a Programmers counterpart: http://programmers.stackexchange.com/questions/101716/in-pseudo-code-what-does-mean – BoltClock Apr 22 '12 at 12:19
@BoltClock'saUnicorn: You should look through the revision history of the question to see what it started out as. In its current state it isn't such a bad question any more IMO, but it was quite funny at the start. – Tim Pietzcker Apr 22 '12 at 16:21

score 11 · Answer 2 · answered Apr 21 '12 at 21:53

11

In pseudo code := means assignment whereas = means equality

a:=1 in pseudo code means a=1 in most languages while, a=1 is generally used for conditional checking in pseudo code i.e. if(a=1) in pseudocode means if (a==1) in most languages.

answered Apr 21 '12 at 21:53

gopi1410

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score 4 · Answer 3 · answered Apr 21 '12 at 21:44

4

If you are talking about translating from another language, the := operator is used in pascal like languages for assigning variables.

In python the equivalent would just be =.

Pascal:

a := 1

Python:

a = 1

answered Apr 21 '12 at 21:44

Slipstream

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score 2 · Answer 4 · edited Apr 22 '12 at 18:02

2

Pascal:

a := 1

Python:

a = 1

:)

edited Apr 22 '12 at 18:02

McGarnagle

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answered Apr 21 '12 at 22:08

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

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What does ":=" mean in Pseudocode?

4 Answers4