identity

identity(x)

The identity function. Returns its argument.

Examples

In the Julia programming language, the identity function simply returns its argument.

julia> identity(5)
5

julia> identity("Hello")
"Hello"

Here are some common examples of using the identity function:

Passing a variable through unchanged:
```
julia> x = 10;
julia> identity(x)
10
```
It returns the value of x unchanged.
Using identity in a function composition:
```
julia> f(x) = x^2;
julia> g(x) = x + 1;
julia> h = f ∘ g ∘ identity;
julia> h(5)
36
```
Here, identity is used in a function composition to pass the intermediate result through unchanged.

Applying identity to arrays:

julia> arr = [1, 2, 3, 4];
julia> result = map(identity, arr);
julia> result
4-element Array{Int64,1}:
1
2
3
4

It can be used with map to create a new array with the same elements.

Common mistake example:

julia> identity(1, 2)
ERROR: MethodError: no method matching identity(::Int64, ::Int64)

In this example, the identity function is called with two arguments, but it only accepts a single argument. Make sure to provide only one argument to the identity function.

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identity

Examples

See Also

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