PHP Code:

<?php
$arrayData = [
    [
        "name"      => "Anto",
        "age"       => 25,
        "email"     => "anto@mail.com"
    ],
    [
        "name"      => "Vengat",
        "age"       => 28,
        "email"     => "vengat@mail.com"
    ]
];
function getArrayLength($arrayData)
{
    $arrayLength = [];
    foreach($arrayData as $data) {
        foreach($data as $column => $value) {
            $strlen = strlen($value);

            if(isset($arrayLength[$column]) AND $arrayLength[$column] < $strlen) {
                $arrayLength[$column] = $strlen;
            } else if(!isset($arrayLength[$column])) {
                $arrayLength[$column] = $strlen;
            }
        }
    }
    return $arrayLength;
}
$arrayLength = getArrayLength($arrayData);
echo "<pre>";
print_r($arrayLength);
echo "</pre>";
?>