CODEWITHSUNDEEP
arraysnode.js
Mukesh Soni
Mukesh Soni

Reputation: 1139

NodeJS: incorrect result of array.join

I noticed incorrect output of array.join with array of strings containing (\r) character. Here's my code and output:

var list = [
"one\r",
"two\r",
"three\r",
"four\r"]
console.log(list); // ok, output: [ 'one\r', 'two\r', 'three\r', 'four\r' ]
console.log(list.join(',')); // incorrect, outputs: ,foure

It works fine in chrome/firefox consoles, just not in nodejs. I'm using node 6.11.3 on linux mint 18.3 if that matters

I can do workarounds for this, but I'm more interested in why this is happening.

Upvotes: 1

Views: 102

Answers (1)

kite.js.org
kite.js.org

Reputation: 1649

Actually the string is joined successfully in your code, the output result ",foure" is caused by char '\r', which called "linefeed", line feed in Linux / macOS terminal moves the cursor to the beginning of a line, so:

  • "one\r" outputs: "one"
  • "one\r,two\r" outputs: "two"
  • "one\r,two\r,three\r" outputs: "three"
  • "one\r,two\r,three\r,four\r" outputs: "foure"

the last char "e" is from "three", \r is not "new line". Use "\n" Carriage Return to output new line, and just put it in "join(',\n')" instead of putting it in elements of array.

var list = [
    "one",
    "two",
    "three",
    "four"];
    console.log(list); // ok, output: [ 'one', 'two', 'three', 'four' ]
    console.log(list.join(',\n'));

Upvotes: 2

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