CODEWITHSUNDEEP
phparraysmultidimensional-arrayfilter
Rex Rex
Rex Rex

Reputation: 1030

Filter a 2d array to keep rows which have a specified column value

I have an array like this:

[0] => Array(
    [student_id] => 6
    [gender] => 1
    [student_name] => name1
)

[1] => Array(
    [student_id] => 26
    [gender] => 2
    [student_name] => name2
)

[2] => Array(
    [student_id] => 75
    [gender] => 2
    [student_name] => name3
)

[3] => Array(
    [student_id] => 1
    [gender] => 1
    [student_name] => name4
)

[4] => Array(
    [student_id] => 10
    [gender] => 1
    [student_name] => name5
)

I would like to list the student names or array keys where gender is 2.

What is the most efficient way to achieve this?

Avoiding foreach should be better.

Upvotes: 1

Views: 98

Answers (5)

KesaVan
KesaVan

Reputation: 1031

Try this

function check_gender($element) {
  return $element['gender'] === gender[2];
}

array_filter(check_gender, $the_array);

Upvotes: 0

Shankar Narayana Damodaran
Shankar Narayana Damodaran

Reputation: 68476

A simple foreach would do..

$searchKey = 2;
foreach($yourarray as $k=>$arr)
{
 if($arr['gender']==$searchKey)
 {
   echo $arr['student_name']."<br>";
 }
}

Demo

One-liner array_map()

As you mentioned you are avoiding a foreach . This function still uses internal loop structures which is hidden. You should probably use the foreach instead as it is easily - readable.

$searchKey=2;
array_map(function($v) use($searchKey) {  if($v['gender']==$searchKey){ echo $v['student_name']."<br>";}}, $yourarray);

Demo

Upvotes: 2

eje211
eje211

Reputation: 2429

For this sort of operation, it's generally a good idea to use a filter:

function check_gender($element) {
  return $element['gender'] === 2;
}

array_filter(check_gender, $the_array);

Keep in mind that anonymous functions are only available from PHP 5.3 on. If you need your code to run on an older version of PHP, you'll need to declare the function first, like in the code above. If you're sure your code will only ever need to run on PHP 5.3 or newer, you can directly place an anonymous function as an argument of array_filter.

Upvotes: 3

xdazz
xdazz

Reputation: 160833

You could use array_filter to filter the array.

$students = array_filter($students, function($var) {
    return $var['gender'] === 2;
});

And if you want to collect the names as an array, there is array_map:

$names = array_map(function($var) {
    return $var['student_name'];
}, $students);

Upvotes: 4

John
John

Reputation: 1490

Assuming the array is unsorted, the best you can do is a simple loop through the array and check each key. Since the array is unsorted, you'll need to check every gender field.

Upvotes: 1

Related Questions