PHP Read CSV To JSON (Simple Examples)

Welcome to a tutorial on how to read a CSV file into a JSON-encoded string in PHP. So you are working on a project that needs to read a CSV file, and maybe send that to an API in JSON format?

Yep, let us walk through a few simple examples – Read on!

 

 

TLDR – QUICK SLIDES

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TABLE OF CONTENTS

 

 

EXAMPLE 1) CSV TO INDEXED ARRAY

1A) DUMMY DATA

Joe Doe	joe@doe.com
Jon Doe	jon@doe.com
Joy Doe	joy@doe.com

For this example, we will be working with this simple CSV list of users.

 

 

1B) NESTED INDEXED ARRAY

<?php
// (A) EXTRACT ROWS & COLS INTO ARRAY
$data = [];
$stream = fopen("1a-dummy.csv", "r");
while (($row = fgetcsv($stream)) !== false) { array_push($data, $row); }
fclose($stream);
 
// (B) JSON ENCODE DATA
print_r($data);
echo json_encode($data);

[["Joe Doe","joe@doe.com"],["Jon Doe","jon@doe.com"],["Joy Doe","joy@doe.com"]]

• Create an empty array $data = [].
• Read the CSV file, use array_push() to collect all the data into $data.
• Lastly, json_encode($data).

Sorry to those who are expecting more, but that’s all. 😆

 

1C) FLAT INDEXED ARRAY

<?php
// (A) EXTRACT ROWS & COLS INTO ARRAY
$data = [];
$stream = fopen("1a-dummy.csv", "r");
while (($row = fgetcsv($stream)) !== false) { array_push($data, ...$row); }
fclose($stream);
 
// (B) JSON ENCODE DATA
print_r($data);
echo json_encode($data);

["Joe Doe","joe@doe.com","Jon Doe","jon@doe.com","Joy Doe","joy@doe.com"]

If you prefer a flat array of values, just spread the values ...$row when collecting the data.

 

 

EXAMPLE 2) CSV TO ASSOCIATIVE ARRAY

2A) DUMMY DATA

NAME	EMAIL
Joe Doe	joe@doe.com
Jon Doe	jon@doe.com
Joy Doe	joy@doe.com

For this example, the first row of the CSV file is the header.

 

2B) SINGLE KEY WITH MULTIPLE VALUES

<?php
// (A) FLAGS & EMPTY ARRAY
$first = true;
$keys = [];
$data = [];
 
// (B) EXTRACT ROWS & COLS INTO ARRAY
$stream = fopen("2a-dummy.csv", "r");
while (($row = fgetcsv($stream)) !== false) {
  // (B1) FIRST ROW IS THE HEADER
  if ($first) {
    foreach ($row as $i=>$col) {
      $keys[] = $col;
      $data[$col] = [];
    }
    $first = false;
  }

  // (B2) FOLLOWING ROWS ARE DATA
  else {
    foreach ($row as $i=>$col) { $data[$keys[$i]][] = $col; }
  }
}
fclose($stream);

// (C) JSON ENCODE DATA
print_r($keys);
print_r($data);
echo json_encode($data);

{"NAME":["Joe Doe","Jon Doe","Joy Doe"],"EMAIL":["joe@doe.com","jon@doe.com","joy@doe.com"]}

Not going to explain line by line, it’s just a matter of how you want to arrange $data. For those who are lost, this is arranged in the format:

• $data["NAME"] = [NAME, NAME, ...]
• $data["EMAIL"] = [EMAIL, EMAIL, ...]

 

 

2C) NESTED INDEXED ARRAY

<?php
// (A) FLAGS & EMPTY ARRAY
$first = true;
$keys;
$data = [];
 
// (B) EXTRACT ROWS & COLS INTO ARRAY
$stream = fopen("2a-dummy.csv", "r");
while (($row = fgetcsv($stream)) !== false) {
  // (B1) FIRST ROW IS THE HEADER
  if ($first) {
    $keys = $row;
    $first = false;
  }
 
  // (B2) FOLLOWING ROWS ARE DATA
  else {
    $r = [];
    foreach ($keys as $i=>$key) { $r[$key] = $row[$i]; }
    $data[] = $r;
  }
}
fclose($stream);
 
// (C) JSON ENCODE DATA
print_r($keys);
print_r($data);
echo json_encode($data);

[{"NAME":"Joe Doe","EMAIL":"joe@doe.com"},{"NAME":"Jon Doe","EMAIL":"jon@doe.com"},{"NAME":"Joy Doe","EMAIL":"joy@doe.com"}]

A final example, this is arranged in:

• $data[0] = ["NAME"=>NAME, "EMAIL"=>EMAIL]
• $data[1] = ["NAME"=>NAME, "EMAIL"=>EMAIL]
• $data[N] = ["NAME"=>NAME, "EMAIL"=>EMAIL]

 

 

 

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EXAMPLE CODE DOWNLOAD

Click here for the source code on GitHub gist, just click on “download zip” or do a git clone. I have released it under the MIT license, so feel free to build on top of it or use it in your own project.

 

 

LINKS & REFERENCES

• Display CSV As Table In PHP – Code Boxx
• Ways To Read Files In PHP – Code Boxx
• fgetcsv – Official PHP Manual

 

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