How to Get the Index of the Current Iteration of a Foreach Loop

How do you get the index of the current iteration of a foreach loop?

The foreach is for iterating over collections that implement IEnumerable. It does this by calling GetEnumerator on the collection, which will return an Enumerator.

This Enumerator has a method and a property:

• MoveNext()
• Current

Current returns the object that Enumerator is currently on, MoveNext updates Current to the next object.

The concept of an index is foreign to the concept of enumeration, and cannot be done.

Because of that, most collections are able to be traversed using an indexer and the for loop construct.

I greatly prefer using a for loop in this situation compared to tracking the index with a local variable.

Get current index from foreach loop

IEnumerable list = DataGridDetail.ItemsSource as IEnumerable;
List<string> lstFile = new List<string>();

int i = 0;
foreach (var row in list)
{
bool IsChecked = (bool)((CheckBox)DataGridDetail.Columns[0].GetCellContent(row)).IsChecked;
if (IsChecked)
{
  MessageBox.show(i);
--Here i want to get the index or current row from the list                   

}
 ++i;
}

How to find the foreach index?

foreach($array as $key=>$value) {
    // do stuff
}

$key is the index of each $array element

How do I get the index of an item inside of a ForEach loop?

You may go this way with an enumerated array:

   struct TempView: View{

   @State var quarters: [[Month]] = [[.init(name: "January", products: ["1", "2"]),.init(name: "February", products: ["1", "2"]),.init(name: "March", products: ["1", "2"])],
[.init(name: "April", products: ["1", "2"]), .init(name: "May", products: ["1", "2"]), .init(name: "June", products: ["1", "2"])]]

  var body: some View {

        ForEach (self.quarters.indices , id: \.self) { (index) in

        VStack {
        Spacer()
            HStack {
                Text("Q\(index)")
                .font(.system(size: 40, weight: .black, design: .rounded))
                Button("TestButton",action: {
                    self.quarters.append([.init(name: "January", products: ["1", "2"]),.init(name: "February", products: ["1", "2"]),.init(name: "March", products: ["1", "2"])])
                })
            }
             Spacer()
        }
    }

 }}                                                                                                

How do you get the index of the current iteration of a foreach loop?

The foreach is for iterating over collections that implement IEnumerable. It does this by calling GetEnumerator on the collection, which will return an Enumerator.

This Enumerator has a method and a property:

• MoveNext()
• Current

Current returns the object that Enumerator is currently on, MoveNext updates Current to the next object.

The concept of an index is foreign to the concept of enumeration, and cannot be done.

Because of that, most collections are able to be traversed using an indexer and the for loop construct.

I greatly prefer using a for loop in this situation compared to tracking the index with a local variable.

Accessing the index in 'for' loops

Use the built-in function enumerate():

for idx, x in enumerate(xs):
    print(idx, x)

It is non-pythonic to manually index via for i in range(len(xs)): x = xs[i] or manually manage an additional state variable.

Check out PEP 279 for more.

Get index of array in foreach loop

You are referencing the array value as an array. That's why it is giving you $row['id']

You need to use $key as that is the value of your current index in the $rows array.

When you use foreach($rows as $key => $row) this is what it is practically doing:

• $rows - input array to loop through
• $key - key of your current location in the first dimensional array
• $row - value of your current location in the first dimensional array

How to get index in C# foreach

You can initialize a local variable outside a foreach loop and increment it until last row. This will hold current row. e.g

int i=0; 
foreach (DataRow row in dt.Rows) 
{

xlWorkSheet.Cells[i, 1] = row["Id"].ToString(); 
i++; 
} 

Get the current index of a for each loop iterating an ArrayList

Just use a traditional for loop:

for (int i = 0; i < yourArrayList.size(); i ++) {
    // i is the index
    // yourArrayList.get(i) is the element
}

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