In PHP Given a Month String Such as "November" How to Return 11 Without Using a 12 Part Switch Statement

In PHP given a month string such as November how can I return 11 without using a 12 part switch statement?

Try

echo date('n', strtotime('November')); // returns 11

If you have to do this often, you might consider using an array that has these values hardcoded:

$months = array( 1 => 'January', 2 => 'February', 3 => 'March', 4 => 'April',
                 5 => 'May',     6 => 'June',     7 => 'July',  8 => 'August',
                 9 => 'September', 10 => 'October', 11 => 'November',
                 12 => 'December');

Can also do it the other way round though, using the names for the keys and numbers for values.

With the names for values you do

echo array_search('November', $months); // returns 11

and with names for keys you do

echo $months['November']; // returns 11

I find using the numbers for the keys somewhat better in general, though for your UseCase the names for keys approach is likely more comfortable. With just 12 values in the array, there shouldn't be much of a difference between the array approches.

A quick benchmark noted a difference of 0.000003s vs 0.000002s, whereas the time conversion takes 0.000060s on my computer (read: might differ on other computer).

PHP convert month

<?php echo date("F",mktime(0,0,0,$member['dob_month'],1,0); ?>

How can I convert month name to number?

$monthName = 'January';
$date = date_parse($monthName);
$monthNumber = $date['month'];

Note that this will return 1, not 01, so change your display format accordingly.

Use an array of ordered date expressions to populate a new array with data from a second array related by its numeric keys

Use array_map() to map the numeric data to the month-year expression. To relate the data's numeric keys to the date expressions, use a datetime class plus a convert method, or just call date(strtotime()).

Code: (Demo) (Classic loop)

var_export(
    array_map(
        fn($My) => $data[date('n', strtotime($My))],
        $forecastedMonths
    )
);

Very relevant page: In PHP given a month string such as "November" how can I return 11 without using a 12 part switch statement?

How to translate specific set of strings in PHP

An array would be useful here, and in this case it would be similar to a hashmap in Java.

$wkday = "Thu";
$wkdayMapper = array(
  "Mon" => "Monday",
  "Tue" => "Tuesday",
  "Wed" => "Wednesday",
  "Thu" => "Thursday",
  "Fri" => "Friday",
  "Sat" => "Saturday",
  "Sun" => "Sunday"
);

echo $wkdayMapper[$wkday]; //Thursday

PHP manual link on arrays

How to shorten switch case block converting a number to a month name?

Define an array, then get by index.

var months = ['January', 'February', ...];

var month = months[mm - 1] || '';

Calculate the number of months between two dates in PHP?

$date1 = '2000-01-25';
$date2 = '2010-02-20';

$ts1 = strtotime($date1);
$ts2 = strtotime($date2);

$year1 = date('Y', $ts1);
$year2 = date('Y', $ts2);

$month1 = date('m', $ts1);
$month2 = date('m', $ts2);

$diff = (($year2 - $year1) * 12) + ($month2 - $month1);

You may want to include the days somewhere too, depending on whether you mean whole months or not. Hope you get the idea though.

How do I check if a string contains a specific word?

Now with PHP 8 you can do this using str_contains:

if (str_contains('How are you', 'are')) { 
    echo 'true';
}

RFC

Before PHP 8

You can use the strpos() function which is used to find the occurrence of one string inside another one:

$haystack = 'How are you?';
$needle   = 'are';

if (strpos($haystack, $needle) !== false) {
    echo 'true';
}

Note that the use of !== false is deliberate (neither != false nor === true will return the desired result); strpos() returns either the offset at which the needle string begins in the haystack string, or the boolean false if the needle isn't found. Since 0 is a valid offset and 0 is "falsey", we can't use simpler constructs like !strpos($a, 'are').

Should switch statements always contain a default clause?

Switch cases should almost always have a default case.

Reasons to use a default

1.To 'catch' an unexpected value

switch(type)
{
    case 1:
        //something
    case 2:
        //something else
    default:
        // unknown type! based on the language,
        // there should probably be some error-handling
        // here, maybe an exception
}

2. To handle 'default' actions, where the cases are for special behavior.

You see this a LOT in menu-driven programs and bash shell scripts. You might also see this when a variable is declared outside the switch-case but not initialized, and each case initializes it to something different. Here the default needs to initialize it too so that down the line code that accesses the variable doesn't raise an error.

3. To show someone reading your code that you've covered that case.

variable = (variable == "value") ? 1 : 2;
switch(variable)
{
    case 1:
        // something
    case 2:
        // something else
    default:
        // will NOT execute because of the line preceding the switch.
}

This was an over-simplified example, but the point is that someone reading the code shouldn't wonder why variable cannot be something other than 1 or 2.

The only case I can think of to NOT use default is when the switch is checking something where its rather obvious every other alternative can be happily ignored

switch(keystroke)
{
    case 'w':
        // move up
    case 'a':
        // move left
    case 's':
        // move down
    case 'd':
        // move right
    // no default really required here
}