Method: 1. Use the in_array() function to detect whether there is a specified element value in the array, the syntax is "in_array(element value, array)"; 2. Use the array_search() function to search in the array Specify element value, syntax "array_search(element value, array)".
The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer
# judge one in php Is the element in the array?
Method 1: Use the in_array() function
The in_array() function can find whether the array contains an Value, returns TRUE if it exists, FALSE if it does not exist. The syntax format is as follows:
in_array($needle, $array[, $strict = FALSE])
The parameter description is as follows:
- $needle: is the value to be searched. If $needle is a string, the comparison is case-sensitive;
- $array: is the array to be searched;
- $strict: is an optional parameter, the default is FALSE.
- If $strict is empty or FALSE, the in_array() function will only check whether the value of $needle is equal to the value in $array;
- If the value of $strict is TRUE, in_array In addition to checking the values in $needle and $array, the () function also compares their types for equality.
Tip: The in_array() function is only suitable for finding an element in a one-dimensional array, and will not recursively search for elements in each dimension of the array.
Example: Use the in_array() function to determine whether the array contains a certain value
<?php header("Content-type:text/html;charset=utf-8"); $sites = array('a', 'b', '1', 2, 3); if (in_array("a", $sites)) { echo "指定元素在数组中"; } else { echo "指定元素不在数组中"; } ?>
2. Use the array_search() function
array_search() function searches for a key value in the array and returns the corresponding key name.
If the specified key value is found in the array, return the corresponding key name, otherwise return FALSE. If a key value is found more than once in the array, the key name matching the first found key value is returned.
The syntax format of this function is as follows:
array_search($needle, $haystack[, $strict = false])
The parameter description is as follows:
- $needle: is the value to be searched, if $needle is a character String type, the search is case-sensitive;
- $haystack: is an array;
- $strict: optional parameter, can be empty, defaults to False.
- If $strict is False, array_search() will only compare values, not types, when searching for $needle in $haystack.
- If $strict is True, array_search() compares both the value and type when searching for $needle in $haystack.
<?php header("Content-type:text/html;charset=utf-8"); $sites = array("a"=>"red","b"=>"green","c"=>"blue"); if (array_search("red",$sites)) { echo "指定元素在数组中"; } else { echo "指定元素不在数组中"; } echo "<br>指定元素的键名为:".array_search("red",$sites); ?> ?>
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