loop and insert into another array without redundancy

Question

How to skip inserting repeating same value of array items in my case? I know there is built in function like array unique but my case is different.

Below code produced 12345555555667 but I just want 1234567, means not a value is duplicate.

$NumArray = array('1','2','3','4','5','5','5','5','5','5','5','6','6','7');
$SecondArray = array();

foreach($NumArray as $num){
    $SecondArray[] = array(
    'alpa'=>$num
    );
}

echo json_encode($SecondArray);

how is your case different? Why wouldn't you be able to use array_unique? — Elias Van Ootegem
– Elias Van Ootegem, Commented Feb 10, 2015 at 15:36
@EliasVanOotegem $numArray's value is not static, it's a loop to construct its array value. — Fernandez
– Fernandez, Commented Feb 10, 2015 at 15:49

Elias Van Ootegem · Accepted Answer · 2015-02-10 16:01:44Z

1

If $NumArray were static, it's as simple as doing:

foreach (array_unique($NumArray) as $num)
{
    //same code as before
}

But given that it isn't, you could just write:

$SecondArray = ();
foreach ($NumArray as $num)
{
    if (!isset($SecondArray[$num]))
    {//key does not exist (yet)
        $SecondArray[$num] = array('alpa' => $num);
    }
}
echo json_encode(array_values($SecondArray));//remove keys, to ensure a JSON array

see the docs

The array_values call ensures the resulting JSON string is a JS array, and not an object. For example, if $num was 1, 2, 3, the JSON string without array_values would've looked like this:

{
 1: {alpha: 1},
 2: {alpha: 2},
 3: {alpha: 3}
}

With that call, it looks like this:

[
 {alpha: 1},
 {alpha: 2},
 {alpha: 3}
]

edited Feb 10, 2015 at 16:01

answered Feb 10, 2015 at 15:31

Elias Van Ootegem

76.7k10 gold badges123 silver badges160 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Fernandez Over a year ago

what if $num aren't just number but real values like people's name?

Elias Van Ootegem Over a year ago

@Fernandez: That doesn't really matter, strings, like numbers, can be used as keys because a PHP array is actually a hash table (sort of like a dictionary in other languages)

GreyRoofPigeon · Accepted Answer · 2015-02-10 16:01:09Z

0

Create a new array, then loop the $NumArray to check if the value already exists... if not, add it to the new array.

<?php
$NumArray = array('1','2','3','4','5','5','5','5','5','5','5','6','6','7');

$newArray = array();
foreach( $NumArray as $val ) {
    if( !in_array( $val, $newArray ) ) {
        $newArray[] = $val;
    }
}
echo '<pre>';
print_r( $newArray );
echo '</pre>';
?>

answered Feb 10, 2015 at 16:01

GreyRoofPigeon

18.1k5 gold badges39 silver badges60 bronze badges

2 Comments

Fernandez Over a year ago

so the key thing here is in_array?

GreyRoofPigeon Over a year ago

Yes, it checks if the value already is in the array or not. If not, it's added.

mgamon · Accepted Answer · 2015-02-10 15:51:18Z

0

What about:

$NumArray = array('1','2','3','4','5','5','5','5','5','5','5','6','6','7');
$SecondArray = array();
foreach($NumArray as $key => $value){
    if(in_array($value, $NumArray){
         array_push($SecondArray, $value);
    }
}
echo json_encode($SecondArray);

edited Feb 10, 2015 at 15:51

answered Feb 10, 2015 at 15:40

mgamon

3087 silver badges16 bronze badges

3 Comments

Elias Van Ootegem Over a year ago

OP mentions he can't use array_unique for some reason (second sentence of the question)

Fernandez Over a year ago

Warning: array_push() expects parameter 1 to be array, null given on line 5

mgamon Over a year ago

@Fernandez Sorry I missed $SecondArray = array();

Collectives™ on Stack Overflow

loop and insert into another array without redundancy

3 Answers 3

2 Comments

2 Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

2 Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related