Reading file in C# based on new line

Question

I have a file in C# which has keywords like this each present on new line

1234-hello I am here
121-Where are you

I want to read the file and write 1234-Hello 121-Where into another file, I have found lot of codes on internet that are based on comma seperated but couldn't find code to extract values on the basis of new line.

The - seperates the Number and the keyword I want to extract, like 1234-hello

Answer 1

You can use this:

string[] lines = File.ReadAllLines(path);
for(int i = 0; i < lines.Length; i++)
{
    string line = lines[i];
    string[] tokens = line.Split(new char[]{'-', ' '});
    int number = int.Parse(tokens[0]);
    string text = tokens[1];
    lines[i] = number + "-" + text;
}

File.WriteAllLines(path2, lines);

You probably want to add some error handling

• Check if any lines are returned
• Check if tokens.Length >= 2
• etc.

Answer 2

First read all lines, Split each line by white-space, get the first part and write the content to the new file:

var lines = File.ReadLines("path").Select(x => x.Split().First());

File.WriteAllLines("otherPath", lines);

This code should produce an output like this:

1234-Hello
121-Where