php json_encode not escaping new lines

I don't believe json_encode is your problem. My guess is your database is interpreting \ as the escape character, so it simply strips them out.

To combat that, simply escape the escape characters using addslashes:

$results=addslashes($results);

Newlines are not valid characters inside of JSON strings. That's the expected behavior:

char

any Unicode character except " or \ or control-character

• \"
• \
• /
• \b
• \f
• \n
• \r
• \t
• \u four-hex-digits

JSON escapes those control characters into those in the list.

So now we have '\n' (literally a backslash followed by 'n'), which, if not escaped properly, will be saved in the database as n. And that is the problem you're experiencing.

The Solution

Use prepared statements to properly escape any and all slashes in the strings you're storing in your database. That will save them as '\n', which you can convert to "\n" when you retrieve your data.

You could manually escape them:

$array = array('name'=> "some text \n\r text");

$results = json_encode(array_filter($array, function($arr) use ($array){
        return preg_replace('~\\[nrtfd]~', '\\\\$1', $arr);
}));

print_r($results);

You could extend your own json_encode function, and replace your uses of json_encode to my_json_encode:

function my_json_encode($json){
    $results = json_encode(array_filter($json, function($arr) use ($array){
        return preg_replace('~\\[nrtfd]~', '\\\\$1', $arr);
    }));

    return $results;
}

print_r($results);

FYI, the above returns: {"name":"some text \n\r text"} instead of {"name":"some text nr text"}

You could use JSON_PRETTY_PRINT as described in the PHP manual.

https://www.php.net/manual/function.json-encode.php

You could use PHP_EOL for a new line. Where to include new line depends on how you want. In the case below, i need a new line after the last closing square bracket and each curly bracket:

tit1: {
"prop1" : [ "", "", []], 
"prop2" : [ "", "", []]
}, 
tit2: {
"prop1" : [ "", "", []], 
"prop2" : [ "", "", []]
}

The function is

$jsonDataTxt = $this->own_format_json($jsonData);
file_put_contents("C:/Users/mm/Documents/Data.json", $jsonDataTxt);


function own_format_json($json, $html = false) {
        $tabcount = 0; 
        $result = ''; 
        $bnew = 0;
        $brack=0;  
        $tab = "\t"; 
        $newline = PHP_EOL; 
        for($i = 0; $i < strlen($json); $i++) { 
            $char = $json[$i]; 
            if($char!==',' && $bnew===1) { $bnew=0; $result.=  $newline; } //insert new line after ], which is not proceeded by ,
            switch($char) { 
                case '{': 
                    $tabcount++; 
                    $result .= $char . $newline . str_repeat($tab, $tabcount); 
                    break; 
                case '}': 
                    $tabcount--; 
                    $result = trim($result) . $newline . str_repeat($tab, $tabcount) . $char . $newline; 
                    break; 
                case '[': 
                    $brack++; 
                    $result .= $char;// . $newline . str_repeat($tab, $tabcount); 
                    break; 
                case ']': 
                    $brack--;
                    $result .= $char;// . $newline . str_repeat($tab, $tabcount); 
                    if($brack===0) { $bnew=1; }
                    //echo "<br><br> case  ]  char=".$char.',   brack='.$brack. ",  bnew=".$bnew.",   result=".$result ; 
                    break; 
                case ',': 
                    $result .= $char;// . $newline . str_repeat($tab, $tabcount); 
                    if($bnew===1) { $bnew=0; $result.=  $newline; } //insert new line after ],
                    break; 
                case '"': 
                    $result .= $char; 
                    break; 
                default: 
                    $result .= $char; 
            } 
        } 
    return $result; 
   }

I use this command to clean the backslashes.

$info = file_get_contents('my_file.txt');
**$info = str_replace(array("r\n","\n", "\r"), "", $info);**    
$info = json_decode($info);

I've found that the simplest solution is to use JSON_UNESCAPED_UNICODE (along with other flags, if you need them). You can learn more about these flags in the documentation

Regarding the original issue:

<?php
$tmp = array();

$tmp[1] = "test";
$tmp["ok"] = "this
seems to be
a
multiline
nightmare,
but
we
can manage it";

$conv = json_encode($tmp,JSON_UNESCAPED_UNICODE);
echo $conv;
?>

which outputs

{"1":"test","ok":"this\r\nseems to be\r\na\r\nmultiline\r\nnightmare,\r\nbut\r\nwe\r\ncan manage it"}