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arrayssortingd

How to sort array of objects in Dlang?

How do I sort an array of user-defined objects in D?

Coming from a C++ background, I suppose you'd have to declare an operator overload for the type stored in the array, or use a comparator function...

An example of how to do it would be much appreciated.

Solution

  • You'll want std.algorithm.sort which uses a < b by default, so your class can override opCmp to take advantage of that.

    Update: Just a alternative to glampert's example.

    import std.algorithm;
import std.stdio;

class Test {

    int x;

    this(int x)
    {
        this.x = x;
    }
}

void main()
{
    Test[] array = [new Test(3), new Test(1), new Test(4), new Test(2)];

    writeln("Before sorting: ");
    writeln(array.map!(x=>x.x));

    sort!((a,b)=>a.x < b.x)(array); // Sort from least to greatest

    writeln("After sorting: ");
    writeln(array.map!(x=>x.x));
}