CODEWITHSUNDEEP
c#string
Hero
Hero

Reputation: 197

Replace String in Specific line in text file

I want to replace String1 with String2 in Text file.

Text File :

This is line no 1. 
This is line no 2. 
This is line no 3.
This is line no 4. 
This is line no 5. 
This is line no 6.

String is :

String1 : no
string2 : number

I want this type of output line 3 to 5 replace with "no" to "number":

This is line no 1. 
This is line no 2. 
This is line number 3.
This is line number 4. 
This is line number 5. 
This is line no 6.

Upvotes: 1

Views: 4788

Answers (3)

fubo
fubo

Reputation: 46005

Another approach with Linq

string[] file = File.ReadAllLines(@"c:\yourfile.txt");
file = file.Select((x, i) => i > 1 && i < 5 ? x.Replace("no", "number") : x).ToArray();
File.WriteAllLines(@"c:\yourfile.txt", file);

Upvotes: 7

Kangjun Heo
Kangjun Heo

Reputation: 1081

System.IO.File.ReadAllLines(string path) may help you.

It creates string array from Text File, you edit the array, and save it with System.IO.File.WriteAllLines.

string[] Strings = File.ReadAllLines(/*File Path Here*/);
Strings[2] = Strings[2].Replace("no", "number");
Strings[3] = Strings[3].Replace("no", "number");
Strings[4] = Strings[4].Replace("no", "number");
File.WriteAllLines(/*File Path Here*/, Strings);

Upvotes: 1

Ivan Kishchenko
Ivan Kishchenko

Reputation: 815

You should try this:

// Read all lines from text file.
String[] lines = File.ReadAllLines("path to file");
for(int i = 3; i <= 5; i++) // From line 3 to line 5
{
    // Replace 'no' to 'number' in 3 - 5 lines
    lines[i - 1] = lines[i - 1].Replace("no", "number");
}

// Rewrite lines to file
File.WriteAllLines("path to file", lines);

Upvotes: 0

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