CSV Escape Unescape

CSV escaping and unescaping refer to encoding and decoding values in a CSV format, typically to handle special characters like commas, quotes, and newlines that can interfere with parsing or display.

CSV Escape/Unescape in Java and .NET
1. CSV Escape and Unescape in Java
In Java, the OpenCSV library is commonly used for working with CSV files. It automatically handles the escaping and unescaping of special characters in CSV files.

However, if you want to manually handle escaping and unescaping CSV strings, here's how you can do it:

CSV Escaping (Escaping special characters for CSV format)
To escape characters such as commas, quotes, and newlines, you need to:

Enclose values with double quotes (")
Escape any double quotes within the value by doubling them (i.e., "")
java

public class CSVEscapeExample {
public static String escapeCSV(String input) {
// Enclose the string in quotes if necessary
if (input.contains(",") || input.contains("\"") || input.contains("\n")) {
input = "\"" + input.replace("\"", "\"\"") + "\"";
}
return input;
}

public static void main(String[] args) {
String input = "Hello, \"World\"";
String escaped = escapeCSV(input);
System.out.println(escaped); // Output: "Hello, ""World"""
}
}
CSV Unescaping (Removing escape sequences from CSV format)
To unescape a CSV string:

Remove surrounding quotes
Replace doubled quotes ("") with a single quote (")
java

public class CSVUnescapeExample {
public static String unescapeCSV(String input) {
// Remove surrounding quotes
if (input.startsWith("\"") && input.endsWith("\"")) {
input = input.substring(1, input.length() - 1);
}
// Replace doubled quotes with a single quote
input = input.replace("\"\"", "\"");
return input;
}

public static void main(String[] args) {
String escaped = "\"Hello, \"\"World\"\"\"";
String unescaped = unescapeCSV(escaped);
System.out.println(unescaped); // Output: Hello, "World"
}
}
2. CSV Escape and Unescape in .NET
In .NET, you can handle CSV escaping and unescaping using the built-in methods for handling strings, or you can manually implement the escaping/unescaping logic.

CSV Escaping (Escaping special characters for CSV format)
In CSV format:

Values containing commas, quotes, or newlines should be enclosed in double quotes (")
Any internal quotes should be doubled ("")
csharp

using System;

public class CSVEscapeExample
{
public static string EscapeCSV(string input)
{
// Enclose the string in quotes if necessary
if (input.Contains(",") || input.Contains("\"") || input.Contains("\n"))
{
input = "\"" + input.Replace("\"", "\"\"") + "\"";
}
return input;
}

public static void Main()
{
string input = "Hello, \"World\"";
string escaped = EscapeCSV(input);
Console.WriteLine(escaped); // Output: "Hello, ""World"""
}
}
CSV Unescaping (Removing escape sequences from CSV format)
To unescape a CSV string:

Remove the surrounding quotes if they exist
Replace doubled quotes ("") with a single quote (")
csharp

using System;

public class CSVUnescapeExample
{
public static string UnescapeCSV(string input)
{
// Remove surrounding quotes
if (input.StartsWith("\"") && input.EndsWith("\""))
{
input = input.Substring(1, input.Length - 2);
}
// Replace doubled quotes with a single quote
input = input.Replace("\"\"", "\"");
return input;
}

public static void Main()
{
string escaped = "\"Hello, \"\"World\"\"\"";
string unescaped = UnescapeCSV(escaped);
Console.WriteLine(unescaped); // Output: Hello, "World"
}
}
Key Points:
Escaping: In CSV, if a string contains special characters like commas, quotes, or newlines, it should be enclosed in double quotes. If the string already contains quotes, those quotes are doubled.
Unescaping: To unescape, you remove the surrounding quotes and replace any doubled quotes with a single quote.
When to Escape/Unescape CSV:
Escape: When writing data to a CSV file, you need to escape any special characters to ensure the CSV format remains valid.
Unescape: When reading a CSV file, you need to unescape the values to retrieve the original data.