检查数组的键是否为null或空字符串的值

Question

I have an array from mysql that I want to echo through variables. I want the raw array to have checked for any null or empty strings to be set as the string " <null> " for personal reasons. But i can't seem to get the expected result. Thanks in advance.

while ($row = mysql_fetch_array($RS2)) {
    foreach ($row as $key => $value) {
        if (empty($value)) {
            $row[$key] = "<null>";
        }
    }
        echo "serno=$row[serno];";
        echo "date=$row[date];";
        echo "time=$row[time];";
        echo "nett=$row[nett];";
        echo "amount=$row[amt];";
        echo "\n";
}

The current outcome when echo out currently looks like this:

serno=1003;date=2018-07-14;time=01:18:57;nett=;amount=500.00;

Expected outcome is:

serno=1003;date=2018-07-14;time=01:18:57;nett=<null>;amount=500.00;

Answer 1

User foreach loop as below:

foreach ($row as $key => $value) {
    $row[$key] = empty($value) ? "" : $value;
}

It will replace empty values to "" .

Answer 2

//I forgot to put else    
$otherArray = array();
while ($row = mysql_fetch_array($RS2)) {
    foreach ($row as $key => $value) {
        if (empty($value)) {
            $otherArray[$key] = "<null>";
        }else{//else here
            otherArray[$key] = $value;
    }

}
    echo "serno=$otherArray[serno];";
    echo "date=$otherArray[date];";
    echo "time=$otherArray[time];";
    echo "nett=$otherArray[nett];";
    echo "amount=$otherArray[amt];";
    echo "\n";

}

Answer 3

You can use a built in function is_null

while ($row = mysql_fetch_array($RS2)) {
    foreach ($row as $key => $value) {
        if (is_null($value)) {
            $var="<null>";
            $row[$key] = htmlspecialchars($var);
        }
    }
        echo "serno=$row[serno];";
        echo "date=$row[date];";
        echo "time=$row[time];";
        echo "nett=$row[nett];";
        echo "amount=$row[amt];";
        echo "\n";
}

Answer 4

//may be like that 
$otherArray = array();
while ($row = mysql_fetch_array($RS2)) {
    foreach ($row as $key => $value) {
        if (empty($value)) {
            $otherArray[$key] = "<null>";
        }
        otherArray[$key] = $value;
    }
    echo "serno=$otherArray[serno];";
    echo "date=$otherArray[date];";
    echo "time=$otherArray[time];";
    echo "nett=$otherArray[nett];";
    echo "amount=$otherArray[amt];";
    echo "\n";
}

Answer 5

foreach($row as $key => $value){
     $row[$key] = !isset($value) ? NULL : $value; }

Use the isset So it easily check for the NULL values