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Programming-Idioms

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Idiom #196 Pass a sub-array

Given an integer array a of size n, pass the first, third, fifth and seventh, ... up to the m th element to a routine foo which sets all these elements to 42.

interface F { void set(int a[], int m); }
F f = (a, m) -> {
    for (int i = 1; i <= m; a[i] = 42, i = i + 2);
};
void foo(int a[], int m) {
    for (int i = 1; i <= m; a[i] = 42, i = i + 2);
}

Passes the entire `a` reference.
void Foo(out int element)
{
    element = 42;
}

for (int i = 0; i < m; i += 2)
{
    Foo(out a[i]);
}

a.Length is the size of a at run-time.

Requires m <= a.Length; the code does not verify this beforehand.

References to individual elements are passed to Foo().

New implementation...
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tkoenig