删除txt文件中的一行（NODE.js）

Question

I make a text file "foo\\nbar\\nbas"

When i append coke(with adding \\n), then the file will be "foo\\nbar\\nbas\\ncoke"

I want to remove the foo.

Help me!

Answer 1

Fo your use case that you have provided, a simple answer is split on \\n, remove the first item, add the new item to the end, and join the array to form your new string.

var parts = "foo\nbar\nbas".split("\n").slice(1);
parts.push("coke");
var updated = parts.join("\n");

Other option is to use indexOf to find the first occurrence of \\n and substring to select the portion of the string, then it is a simple concatenation.

var str = "foo\nbar\nbas";
var position = str.indexOf("\n")+1;
var updated = str.substring(position) + "\ncoke";

Answer 2

You can use simple string manipulation if your task is not complicated by further constraints. Such is as follows:

var fileContents = "foo\nbar\nbas";

// Read Text File, in this case, I have set it.

fileContents = fileContents.replace("foo\n", "");

fileContents += "\ncoke";

// Write back to file