PHP Find Values from Key

Question

So, I'm trying to understand how can I do this. I'm having a hard time with it.

$arrayChart = array(
array(
    "Name" => "Mike",
    "ID" => "0001234",
    "Hours" => 38
    ),
array(
    "Name" => "Miles",
    "ID" => "0005678",
    "Hours" => 42
    )
);

I want to be able to find the hours (integer) from the key values. The thing is that I want to find it based on the first letter of the names. Which means that if I have "M", every name that start with "M" I should output their working hours for the week and add them together.

So, I'm given "M", I have to find from that their working hours and add them. How can I do that? I tried using this function but that doesn't even do anything.

$name = "M";
foreach($arrayChart as $key){
if($key["Name"] == $name){
    $hours = $key["Hours"];
    break;
 }
}
print_r($hours);

Answer 1

Get the first character of $key['Name'] and then compare it to the variable $name. If there is a match, then add $key['Hours'] to a variable. Keep on doing that for each item in arrayChart.

$name = "M";
$hours = 0;

foreach($arrayChart as $key){
    if ($key['Name'][0] === $name) {
        $hours += $key["Hours"];
    }   
}
print_r($hours);

Example: https://rextester.com/VFPH10481

Also check out this question: Getting the first character of a string with $str[0]

EDIT

If $name = "Mike" is a requirement, you could do this:

$name = 'M';
$hours = 0;

foreach($arrayChart as $key){
    
    $foundAtPosition = strpos($key['Name'], $name);
    if ($foundAtPosition === false ||
        $foundAtPosition > 0) {
        continue;
    }
    
    $hours += $key["Hours"];
}
print_r($hours);

Example: https://rextester.com/ZHCG76001

Explanation: Check out the manual for strpos function. Using that function, you can find the position where $name is found in your $key['Name']. If it is not found, strpos will result in false. If it is found, strpos will tell you where it is found.

strpos will show 0 if $name occurs at the beginning. Using that logic, you can ask your loop to skip if result of strpos is false or greater than 0. Otherwise, you can calculate hours.

If you want case-insensitive search, use stripos function instead.

EDIT 2

If you want to extract IDs along with hours, you could do this:

$name = 'M';
$hours = 0;
$ids = array();

foreach($arrayChart as $key){

    $foundAtPosition = strpos($key['Name'], $name);
    if ($foundAtPosition === false ||
        $foundAtPosition > 0) {
        continue;
    }   

    $hours += $key["Hours"];
    $ids[] = $key['ID'];
}
echo $hours . "\n";
echo join(',', $ids) . "\n";

Example: https://rextester.com/ZRIC46050

Explanation: We create an empty array variable called $ids. When we find our match, we add the ID of Mike or M (or whatever you are matching) into the array. $ids[] = 'something' means, add something at the end of $ids variable. To print that variable as a comma-separated value use the join function, which joins each item of the array using a comma in the above code.