How can I make this function shorter?

Question

I'm having some trouble with this function in PHP. I have a changing amount of posted items on this page, and I'm returning the variable in the array with this function:

function grade($a) {
    if ($a == 1) {
        return $_POST['1'];
    }
    if ($a == 2) {
        return $_POST['2'];
    }
    if ($a == 3) {
        return $_POST['3'];
    }
    if ($a == 4) {
        return $_POST['4'];
    }
    if ($a == 5) {
        return $_POST['5'];
    }
    if ($a == 6) {
        return $_POST['6'];
    }
    //... you get the idea
}

This is probably not the right way. How can I make this function shorter so that I don't have to make the if-statement for every possible array variable?

Thanks for you help!

Generally you should not name fields as numbers. You should just call the field grade so that you can just get it out of the post `echo $_POST["grade"];`. — Logan Murphy, May 08 '14 at 19:41
what is this? an attempt at setting the world record for the question with the most amount of answers that say exactly the same? — martskins, May 08 '14 at 19:45
@lascort I think most of the people answering are trying to relive the experience of performing trivial and nonsensical tasks that only a classroom environment could dish out. — MonkeyZeus, May 08 '14 at 19:50

score 7 · Accepted Answer · edited Jun 20 '20 at 09:12

7

You can accomplish this very easily by using the value of the variable as the array key:

function grade($a) {
    if (!array_key_exists($a, $_POST)) {
        // Given grade key does not exist in the $_POST array
        return null;
    }
    return $_POST[$a];
}

You will note that you do not have to convert the integer to a string, as per the documentation:

Additionally the following key casts will occur:

Strings containing valid integers will be cast to the integer type. E.g. the key "8" will actually be stored under 8.

edited Jun 20 '20 at 09:12

Community

1
1

answered May 08 '14 at 19:39

1

You might have to do "$a" since these are strings – Logan Murphy May 08 '14 at 19:39
Woah is it that simple? Can you put a variable in an array like that? Thanks for your help by the way! – Cubes May 08 '14 at 19:40
3

@LoganMurphy PHP will type juggle. – vvanasten May 08 '14 at 19:40
@user3617942 You dont put the variable. you use the value of the variable as the index of your array. – Logan Murphy May 08 '14 at 19:42
+1: This is correct. I would change the `if` statement to `if(array_key_exists(...))`. I think it's better than explicitly returning null (as the function is going to return null if nothing else is returned). – Amal Murali May 08 '14 at 19:50

score 3 · Answer 2 · answered May 08 '14 at 19:39

3

Pretty simple, you just pass the variable on to the return:

function grade($a) {
    if( !isset( $_POST[$a] ) )
        return 0;
    return $_POST[$a];
}

This also checks if it doesn't exist, to return 0 as your grade.

answered May 08 '14 at 19:39

Sunny Patel

7,830
2
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score 2 · Answer 3 · edited May 08 '14 at 19:45

2

You could use a switch operator : http://www.php.net/manual/fr/control-structures.switch.php

I'm not using php but this may work as well :

function grade($a) {
    return $_POST['' . $a];
}

edited May 08 '14 at 19:45

Logan Murphy

6,120
3
24
42

answered May 08 '14 at 19:41

Alexandre FILLATRE

1,305
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20

This is the same as doing `return $_POST[$a]`. How does this answer the question? – Amal Murali May 08 '14 at 19:47
it does answer the question, it concatenates a useless empty string though, but it does answer the question (as all of the other answers in here already) – martskins May 08 '14 at 19:48
I didn't know that $a could be read as a String or a char without that concatenation. Now I do, and that strval($a) does it too. Thanks – Alexandre FILLATRE May 08 '14 at 19:52

score 2 · Answer 4 · answered May 08 '14 at 19:41

2

make it simple:

function grade($a) {
  return isset($_POST[$a]) ? $_POST[$a] : '' ;
}

answered May 08 '14 at 19:41

Awlad Liton

9,366
2
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score 2 · Answer 5 · answered May 08 '14 at 19:45

2

Ternary if would be the shortest.

function grade($a)
{
    return isset($_POST[$a])? $_POST[$a] : null;
}

answered May 08 '14 at 19:45

score 0 · Answer 6 · edited May 08 '14 at 19:45

0

Your can write like bellow

function grade($a) { 
    return $_POST[$a];
}

edited May 08 '14 at 19:45

Logan Murphy

6,120
3
24
42

answered May 08 '14 at 19:41

Anowar Hossain

583
4
17

The OP only wants to return a value if `$a` exists inside `$_POST`. Your function does not check for its existence. – Amal Murali May 08 '14 at 19:47
ys. you are right. Af first i should check that value of `$a` is exist or not. – Anowar Hossain May 08 '14 at 19:50

score 0 · Answer 7 · answered May 08 '14 at 19:54

0

function grade($a) {
    if (isset($_POST[$a])) {
        return $_POST[$a];
    }
    return false;
}

answered May 08 '14 at 19:54

shyammakwana.me

5,562
2
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It is, however, an attempt at a solution that won't work, since the keys in _POST are strings, not ints. – David Berry May 08 '14 at 20:58
@david thanks for correction, another option we can use is `array_key_exists`. – shyammakwana.me May 09 '14 at 05:42

How can I make this function shorter?

7 Answers7