Changing the value of an array through a foreach statement VB.net

Question

I am making a program that automates the seperation of a csv file. We read the csv in through and then assign the "line" using a split command to an array. After that we go through each "cell" in the array and put an = in front because this causes leading zeros not to be lost. Here's the code.

        arLine = line.Split(replace)

        For Each cell As String In arLine
            cell = cell.Replace(",", "")
            cell = String.Format(cellFormat, cell)
        Next

arLine is the array and replace is the delimiter, in this case a pipe not that it matters.'

When it goes through, the arLine is correct but the values in each cell are not changing, any thoughts? newer to VB.net and need direction

Answer 1

Try with this.

arLine = line.Split(replace)          
For x as Integer = 0 To arLine.Lenght - 1             
    arLine(x) = arLine(x).Replace(",", "")             
    arLine(x) = String.Format(cellFormat, arLine(x))         
Next 

You are looping using For Each and trying to modify the value returned by the iterator, but this creates a new string for your cell var, so you are not referencing the original array. Instead, using a traditional for - loop, you could update directly the values in the arLine array

Answer 2

Strings in .NET are immutable. When you modify a string, you actually create a brand-new string.

So, cell no longer refers to the original array element. Instead, try a for loop rather than a foreach loop and assign the modified value back to arLine(i).

Use a for loop rather than foreach so that you have a handy index into the collection.