배열 값이 있는지 확인하는 방법은 무엇입니까?

배열 값이 있는지 확인하는 방법은 무엇입니까?

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또는 $something['say']값이 있는지 어떻게 확인할 수 있습니까?'bla''omg'

$something = array('say' => 'bla', 'say' => 'omg');

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사용 if?

if(isset($something['say']) && $something['say'] == 'bla') {
    // do something
}

Btw, 키로 값을 say두 번 할당 하므로 배열이 하나의 값만 가진 배열이됩니다.

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PHP in_array 함수를 사용할 수 있습니다.

if( in_array( "bla" ,$yourarray ) )
{
    echo "has bla";
}

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사용 : in_array()

$search_array = array('user_from','lucky_draw_id','prize_id');

if (in_array('prize_id', $search_array)) {
    echo "The 'prize_id' element is in the array";
}

다음은 출력입니다. The 'prize_id' element is in the array

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사용 : array_key_exists()

$search_array = array('user_from','lucky_draw_id','prize_id');

if (array_key_exists('prize_id', $search_array)) {
    echo "The 'prize_id' element is in the array";
}

출력 없음

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결론적 array_key_exists()으로 간단한 배열에서는 작동하지 않습니다. 배열 키가 있는지 여부를 찾는 것뿐입니다. in_array()대신 사용하십시오 .

다음은 더 많은 예입니다.

<?php
/**++++++++++++++++++++++++++++++++++++++++++++++
 * 1. example with assoc array using in_array
 *
 * IMPORTANT NOTE: in_array is case-sensitive
 * in_array — Checks if a value exists in an array
 *
 * DOES NOT WORK FOR MULTI-DIMENSIONAL ARRAY
 *++++++++++++++++++++++++++++++++++++++++++++++
 */
$something = array('a' => 'bla', 'b' => 'omg');
if (in_array('omg', $something)) {
    echo "|1| The 'omg' value found in the assoc array ||";
}

/**++++++++++++++++++++++++++++++++++++++++++++++
 * 2. example with index array using in_array
 *
 * IMPORTANT NOTE: in_array is case-sensitive
 * in_array — Checks if a value exists in an array
 *
 * DOES NOT WORK FOR MULTI-DIMENSIONAL ARRAY
 *++++++++++++++++++++++++++++++++++++++++++++++
 */
$something = array('bla', 'omg');
if (in_array('omg', $something)) {
    echo "|2| The 'omg' value found in the index array ||";
}

/**++++++++++++++++++++++++++++++++++++++++++++++
 * 3. trying with array_search
 *
 * array_search — Searches the array for a given value 
 * and returns the corresponding key if successful
 *
 * DOES NOT WORK FOR MULTI-DIMENSIONAL ARRAY
 *++++++++++++++++++++++++++++++++++++++++++++++
 */
$something = array('a' => 'bla', 'b' => 'omg');
if (array_search('bla', $something)) {
    echo "|3| The 'bla' value found in the assoc array ||";
}

/**++++++++++++++++++++++++++++++++++++++++++++++
 * 4. trying with isset (fastest ever)
 *
 * isset — Determine if a variable is set and 
 * is not NULL
 *++++++++++++++++++++++++++++++++++++++++++++++
 */
$something = array('a' => 'bla', 'b' => 'omg');
if($something['a']=='bla'){
    echo "|4| Yeah!! 'bla' found in array ||";
}

/**
 * OUTPUT:
 * |1| The 'omg' element value found in the assoc array ||
 * |2| The 'omg' element value found in the index array ||
 * |3| The 'bla' element value found in the assoc array ||
 * |4| Yeah!! 'bla' found in array ||
 */
?>

여기 있습니다 PHP DEMO

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당신이 사용할 수있는:

• array_search()
• in_array()
• 의 조합 array_flip()및array_key_exists()

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색인이 정의되었는지 확인하려면 다음을 수행하십시오. isset($something['say'])

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You can test whether an array has a certain element at all or not with isset() or sometimes even better array_key_exists() (the documentation explains the differences). If you can't be sure if the array has an element with the index 'say' you should test that first or you might get 'warning: undefined index....' messages.

As for the test whether the element's value is equal to a string you can use == or (again sometimes better) the identity operator === which doesn't allow type juggling.

if( isset($something['say']) && 'bla'===$something['say'] ) {
  // ...
}

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in_array() is fine if you're only checking but if you need to check that a value exists and return the associated key, array_search is a better option.

$data = [
    'hello',
    'world'
];

$key = array_search('world', $data);

if ($key) {
    echo 'Key is ' . $key;
} else {
    echo 'Key not found';
}

This will print "Key is 1"

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<?php
if (in_array('your_variable', $Your_array)) {
    $redImg = 'true code here';
} else {
    $redImg = 'false code here';
} 
?>

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Just use the PHP function array_key_exists()

<?php
$search_array = array('first' => 1, 'second' => 4);
if (array_key_exists('first', $search_array)) {
    echo "The 'first' element is in the array";
}
?>

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Well, first off an associative array can only have a key defined once, so this array would never exist. Otherwise, just use in_array() to determine if that specific array element is in an array of possible solutions.

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bool in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] )

Another use of in_array in_array() with an array as needle

<?php
$a = array(array('p', 'h'), array('p', 'r'), 'o');

if (in_array(array('p', 'h'), $a)) {
    echo "'ph' was found\n";
}

if (in_array(array('f', 'i'), $a)) {
    echo "'fi' was found\n";
}

if (in_array('o', $a)) {
    echo "'o' was found\n";
}
?>

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Assuming you are using a simple array

. i.e.

$MyArray = array("red","blue","green");

You can use this function

function val_in_arr($val,$arr){
  foreach($arr as $arr_val){
    if($arr_val == $val){
      return true;
    }
  }
  return false;
}

Usage:

val_in_arr("red",$MyArray); //returns true
val_in_arr("brown",$MyArray); //returns false

참고URL : https://stackoverflow.com/questions/2440506/how-to-check-if-an-array-value-exists