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Re: := vs = in some function definitions

On Oct 20, 10:06 am, Sam Takoy <sam.ta... at> wrote:

> Have read everything I could find regarding delayed assignment, I'm
> still not quite sure when to use which.
> For example, in the definition
> f[x_] = IdentityMatrix[50].Append[Range[1, 49], x];
> could there ever be any reason to use :=   ?

If x has a value when you evaluate your definition, il will be used in
the definition, which is not usually what you want.
For example, try :

x = 4

Clear@f; f@x_ = 2 x


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