PHP json_last_error_msg() Function

The PHP json_last_error_msg() function returns the error string of the last json_encode() or json_decode() call.

Syntax

json_last_error_msg()

Parameters

No parameter is required.

Return Value

Returns the error message on success, or "No error" if no error has occurred.

Example: json_last_error_msg() example

The example below shows the usage of json_last_error_msg() function.

<?php
//a valid json string
$jsonObj[] = '{"a":10}';

//an invalid json string - 
//using ' instead of " for quotation
//this will cause syntax error
$jsonObj[] = "{'b':20}";

foreach ($jsonObj as $string) {
  echo 'Decoding: '.$string;
  json_decode($string);

  if (json_last_error() !== JSON_ERROR_NONE) {
    echo " - ".json_last_error_msg();
  }
  echo PHP_EOL;
}
?>

The output of the above code will be:

Decoding: {"a":10}
Decoding: {'b':20} - Syntax error

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