Re: If-statement problems
- To: mathgroup at smc.vnet.net
- Subject: [mg49528] Re: If-statement problems
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Thu, 22 Jul 2004 02:47:06 -0400 (EDT)
- Organization: The University of Western Australia
- References: <cdlj0l$83c$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <cdlj0l$83c$1 at smc.vnet.net>,
"Aaron Fude" <aaronfude at yahoo.com> wrote:
> New to Mathematica. I can't figure out how to use the if-statement for pure
> flow control.
It's usually better to use Switch.
> Here's an example:
>
> A = {5, 6, 7, 8}
> For [n = 1, n <= 4, n++,
> if [n == 1, a = A[[n]]];
> if [n == 2, b = A[[n]]];
> if [n == 3, c = A[[n]]];
> if [n == 4, d = A[[n]]];
> ]
>
> I want to assign to a b c and d the 4 values from A. Obviously, that's not
> what happens. How do I accomplish what I need?
You could use
A = {5, 6, 7, 8};
For [n = 1, n <= 4, n++,
Switch[n,
1, a = A[[n]],
2, b = A[[n]],
3, c = A[[n]],
4, d = A[[n]]]
]
However, it is much simpler to use Set directly. First clear the values:
Clear[a,b,c,d]
Then use Set:
{a,b,c,d} = A
Cheers,
Paul
--
Paul Abbott Phone: +61 8 9380 2734
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