How can I shorten my code with isset values

Question

Im am so lost. Can anyone explain how i can shorten this code. I have hundreds of these! I submit a form with input value. Whenever i dont fill in a value, i get an error. So i made these isset blocks to prevent returning the error. But i seem so unefficient! Please help...thanks

if(isset($_POST['input74'])){
$value74 = $_POST['input74'];
}else{
$value74 = "";#default value
}

if(isset($_POST['input75'])){
$value75 = $_POST['input75'];
}else{
$value75 = "";#default value
}

if(isset($_POST['input76'])){
$value76 = $_POST['input76'];
}else{
$value76 = "";#default value

Answer 1

you could wrap the isset in a function like this

function myIsset(&$variable, $default = "")
{
    if(isset($variable))
    {
        return $variable;
    }
    else
    {
        return $default;
    }
}

then you just call it like $value74 = myIsset($_POST['input74']);

the second argument defaults to an empty string so if you want to set the default value you can supply it or change what the default is in the function header if they will just all be the same. bellow is a screen shot showing the code working

while yes you are still going to have one line per $_POST at least you exchnge 5 lines of code with 1 line of code and the function above. you can possibly reduce this to a loop like how i explain in this answer however without seeing the form and confirming any pattern i can't give any code examples for that since what you have shown could just be a coincidence

Answer 2

PHP 7 has a new operator to address this specific situation: the null coalesce operator (??) replaces this:

$foo = isset($foo) ? $foo : $bar

With this:

$foo = $foo ?? $bar;

Answer 3

PHP has support for arrays in forms. You can name your form fields with indexes, e.g. <input type="text" name="input[74]" ... />. Then in PHP, you can access those with a for or foreach loop, because they will be available as an array (i.e. you will have $_POST["input"][74]). You could thus write something like:

$values = $_POST["input"];
for ($i = 0; $i < MAX_INPUTS; $i++) {
  if (!isset($values[$i])) {
    $values[$i] = "";  // default value
  }
}

If for some reason you can't change the HTML side, you could still use a loop to dynamically create the field names and copy the data to an array on the PHP side, something like:

$value = array();
for ($i = 0; $i < MAX_INPUTS; $i++) {
  $name = sprintf("input%d", $i);
  if (isset($_POST[$name])) {
    $value[$i] = $_POST[$name];
  } else {
    $value[$i] = "";  // default
  }
}

In both proposed solutions, you only have some lines of code instead of dozens of repetitions of almost the same lines. In both examples, I assumes that your fields start with input0 and that there is a total of MAX_INPUTS fields. If not all fields exist (e.g. you only have input1, intput2, input74 and input75), you can create an array with the fields numbers:

$field_list = array(1,2,74,75);

And then use that to check your data (here the example with arrays in HTML field names):

$values = $_POST["input"];
foreach ($field_list as $num) {
  if (!isset($values[$num])) {
    $values[$num] = "";  // default value
  }
}

Answer 4

Use ternaries to shorten the code:

$value74 = isset($_POST['input74']) ? $_POST['input74'] : 'Default value';
$value75 = isset($_POST['input75']) ? $_POST['input75'] : 'Default value';
$value76 = isset($_POST['input76']) ? $_POST['input76'] : 'Default value';

Or you could loop through $_POST array as well, but some filtering/validation must be done. Quick idea:

if(!empty($_POST)) {
    $i = 0;
    $arr = array();
    foreach($_POST as $input) {
        $arr[$i] = $input;
        $i++;
    }
}

$arr would then produce an array like

Array
(
    [74] => 'value74'
    [75] => 'value75'
    [76] => 'value76'
)

Answer 5

You could use array_merge.

You would set up your default array with all the default input values provided.

$aryDefault = ['input74'=>'', 'input75'=>'',...]

Then array_merge this with your post array, and it will fill in all the missing values. NOTE: Order is important check out the docs.

If the input arrays have the same string keys, then the later value for that key will overwrite the previous one. If, however, the arrays contain numeric keys, the later value will not overwrite the original value, but will be appended.

Use array_merge($aryDefault, $_POST) so that $_POST overwrites the defaults.

Also, you can use variable variables so you can do this in a loop. If all your variable are named after your array keys, like in your example.

Full Code:

$aryDefault = ['input74'=>'', 'input75'=>'',...];
$aryFinal = array_merge($aryDefaults, $_POST);
foreach( $aryFinal as $key=>$value){
  $$key = $value;
}

You could even generate $aryDefault with a loop, if its super big.

$aryDefault = array();
for(i=0;i<=100;i++){
  $aryDefault["input$i"] = "";
}

Answer 6

If I understand you correctly seeing that you want to set a variable to post or otherwise default value you can do it following the below structure:

$variable = isset($_POST['name']) ? $_POST['name] : "defaultvalue";

That will set the variable of it exists otherwise set the default value specified. I hope this helps.

Answer 7

You can create a simple function to encapsulate the code before PHP 7:

function post($key, $default = null){
    return isset ($_POST[$key])?$_POST[$key]:$default;
}

Since PHP 7 (using the null coalescing operator (??)):

function post($key, $default = null){
    return $_POST[$key] ?? $default;
}

or better whithout function just simple (as mentioned above)

$value74 = $_POST['input74'] ?? ''; #default value
$value75 = $_POST['input75'] ?? ''; #default value
$value76 = $_POST['input76'] ?? ''; #default value