Try this:
var lst = array2D.SelectMany((x,r) => x.Select((a,c)=> new {a,b=new Point(c,r)})
.Where(a=>a.a==0)
.Select(a=>a.b)).ToList();
문제
This is 2D array:
int[][] array2D = new int[7][];
for (int i = 0; i < 7; i++)
array2D[i] = new int[7];
How can I turn the following into a LINQ query, or use enumerable methods to achieve the same output?
var lst = new List<Point>();
for (int r = 0; r < array2D.Length; r++)
for (int c = 0; c < array2D[r].Length; c++)
if (array2D[r][c] == 0)
lst.Add(new Point(c, r));
EDIT - Solution based on @'King King's answer
var lst = m_boardArr.SelectMany((row, rowIndex) =>
row.Select((val, colIndex) =>
new { val, point = new Point(colIndex, rowIndex) })
.Where(col => col.val == 0)
.Select(col => col.point)).ToList();
해결책
Try this:
var lst = array2D.SelectMany((x,r) => x.Select((a,c)=> new {a,b=new Point(c,r)})
.Where(a=>a.a==0)
.Select(a=>a.b)).ToList();
다른 팁
The trick is to use the Select
and SelectMany
that capture the loop variables into an anonymous type, then get those properties back later after the Where
clause, thus:
var list = array2D
.SelectMany((row, r) => row
.Select((el, c) =>
new {Element = el, ColIndex = c, RowIndex = r})
.Where(thing => thing.Element == 0)
.Select(thing => new Point(thing.RowIndex, thing.ColIndex)))
.ToList();
EDIT: Bartosz's comment applies to this solution as well. Unreadable!
var lst = array2D
.SelectMany((innerArray, r)
=> Enumerable
.Range(0, innerArray.Length)
.Where(c => innerArray[c] == 0)
.Select(c => new Point(c, r)))
.ToList();
However, your current solution is more readable.