PHP determines whether a certain value in an array exists

PHP in_array() function checks whether a certain value exists in the array. If it exists, it returns TRUE, otherwise it returns FALSE.

Syntax:

bool in_array( mixed needle, array array [, bool strict] )

Parameter description:

Example:

<?php
$arr_a = array("a", "b", "c", 1);
if(in_array("a", $arr_a)){
  echo &#39;字符 a 在 $arr_a 数组中存在&#39;;
} else {
  echo &#39;字符 a 在 $arr_a 数组中不存在&#39;;
}
?>

Character a Strictly checked example exists in $arr_a array:

<?php
$arr_a = array("a", "b", "c", 1);
if(in_array("1", $arr_a, TRUE)){
  echo &#39;字符 1 在 $arr_a 数组中存在&#39;;
} else {
  echo &#39;字符 1 在 $arr_a 数组中不存在&#39;;
}
?>

Character 1 Example of array as needle that does not exist in $arr_a array:

<?php
$arr_a = array(array("a", "b"), 1, 2);
$arr_b = array("a", "b");
if(in_array($arr_b, $arr_a)){
    echo &#39;数组 $arr_b 在 $arr_a 数组中存在&#39;;
} else {
    echo &#39;数组 $arr_b 在 $arr_a 数组中不存在&#39;;
}
?>

Array $arr_b exists in $arr_a array.

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