php經常使用函數

時間  2021-08-13
標籤 php 數組 app ide 函數 spa 操作系統 指針 排序 欄目 PHP 简体版
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array_combine
功能：用一個數組的值做爲新數組的鍵名，另外一個數組的值做爲新數組的值
案例：php

<?php
$a = array("one","two","three");
$b = array("一","二","三");
$c = array_combine($a,$b);
print_r($c);
/**結果
*Array ( [one] => 一 [two] => 二 [three] => 三 )
*/

 


array_chunk
功能：拆分數組成多個數組數組

<?php
$input_array = array("a"=>"apple","b"=>"blue","c","d","e");
echo "<pre>";
print_r(array_chunk($input_array, 2));
print_r(array_chunk($input_array, 2,True));
echo "</pre>";
/**結果
Array
(
    [0] => Array
        (
            [0] => apple
            [1] => blue
        )

    [1] => Array
        (
            [0] => c
            [1] => d
        )

    [2] => Array
        (
            [0] => e
        )

)
Array
(
    [0] => Array
        (
            [a] => apple
            [b] => blue
        )

    [1] => Array
        (
            [0] => c
            [1] => d
        )

    [2] => Array
        (
            [2] => e
        )

)
*/

 


array_count_values
功能：統計數組中值出現的次數app

<?php
$input_array = array("a"=>"apple","b"=>"blue","c","d","e");
echo "<pre>";
print_r(array_count_values($input_array));
echo "</pre>";
/**結果
Array
(
    [apple] => 1
    [blue] => 1
    [c] => 1
    [d] => 1
    [e] => 1
)
*/

 



array_diff
功能：第一個數組中去掉第二個數組中有的數據，返回剩下的內容做爲結果ide

<?php
$array1 = array("a"=>"apple","b"=>"blue","c","d","e");
$array2 = array("apple","c","d","f");
$result = array_diff($array1, $array2);
$result2 = array_diff($array2, $array1);
echo "<pre>";
print_r($result);//數組1中去掉數組2中剩下的
print_r($result2);//數組2中去掉數組1中剩下的
echo "</pre>";
/**結果
Array
(
    [b] => blue
    [2] => e
)
Array
(
    [3] => f
)
*/

 

array_map
功能：將回調函數執行到數組中函數

<?php
//定義回調函數
function cube($n){
    return ($n*$n*$n);
}
$a = array(1,2,3,4,5);
$b = array_map("cube",$a);
echo "<pre>";
print_r($b);
echo "</pre>";

/**結果
Array
(
    [0] => 1
    [1] => 8
    [2] => 27
    [3] => 64
    [4] => 125
)
*/

 



array_merge
功能：合併一個或多個數組
說明：若是後面有鍵名相同的會覆蓋掉前面的內容，鍵名爲數字的會添加到後面ui

<?php
$array1 = array("color"=>"red",2,4);
$array2 = array("a","b","color"=>"green","shape"=>"trapezoid",4);
$result1 = array_merge($array1,$array2);
$result2 = array_merge_recursive($array1,$array2);
echo "<pre>";
print_r($result1);
print_r($result2);
echo "</pre>";

/**結果
Array
(
    [color] => green
    [0] => 2
    [1] => 4
    [2] => a
    [3] => b
    [shape] => trapezoid
    [4] => 4
)
Array
(
    [color] => Array
        (
            [0] => red
            [1] => green
        )

    [0] => 2
    [1] => 4
    [2] => a
    [3] => b
    [shape] => trapezoid
    [4] => 4
)
*/

 



array_pop
功能：剔除數組最後一個元素，返回被剔除的元素內容spa

<?php
$stack = array("orange","banana","apple","1");
$last = array_pop($stack);
echo "<pre>";
print_r($stack);
print_r($last);
echo "</pre>";

/**結果
Array
(
    [0] => orange
    [1] => banana
    [2] => apple
)
1
*/

 



array_push
功能：將一個多個單元壓入數組末尾，返回以後的數組個數操作系統

<?php
$stack = array("orange","banana");
$count = array_push($stack,"apple","red","blue");
echo "<pre>";
print_r($stack);
print_r($count);
echo "</pre>";

/**結果
Array
(
    [0] => orange
    [1] => banana
    [2] => apple
    [3] => red
    [4] => blue
)
5
*/

 



array_rand
功能：獲取隨機的鍵名指針

<?php
$input = array("orange","banana","apple","red","blue");
$rand = array_rand($input,2);;
print_r($rand);
$rand = array_rand($input,3);
print_r($rand);

/**結果
Array
(
    [0] => 1
    [1] => 4
)
Array
(
    [0] => 0
    [1] => 1
    [2] => 3
)

*/

 



array_search
功能：查詢數組中的內容，返回鍵值，若是有多個匹配，返回第一個匹配的內容排序

<?php
$array = array("blue"=>"b","red"=>"r","green","r");
$key = array_search('b', $array);
echo $key;
echo "<br>";
$key = array_search('r', $array);
echo $key;
echo "<br>";
/**結果
blue
red
*/

 


array_shift
功能：移除開頭的元素，與array_pop相反

<?php
$fruit = array("milk","orange","banana","apple");
$top = array_shift($fruit);
print_r($top);
echo "<br>";
print_r($fruit);

/**結果
milk
Array ( [0] => orange [1] => banana [2] => apple )
*/

 

array_unique
功能：去除數組重複的元素，保留第一個出現的，包括鍵名和值

<?php
$input = array("a"=>"green","red","b"=>"green","blue","c"=>"red");
$result = array_unique($input);
print_r($result);
echo "<br>";
print_r($input);

/**結果
Array ( [a] => green [0] => red [1] => blue )
Array ( [a] => green [0] => red [b] => green [1] => blue [c] => red )
*/

 



array_slice

功能：從數組中取出部分元素
<?php
$input = array("a","b","c","d","e");
$output = array_slice($input,2);//第二個參數沒有時，表示取到最後一個元素
print_r($output);
echo "<br>";
$output = array_slice($input,-2,1);//第二個參數是正數時，表示個數；倒數第一個是-1，倒數第二個是-2
print_r($output);
echo "<br>";
$output = array_slice($input,0,3);
print_r($output);
echo "<br>";
$output = array_slice($input,2,-1);//第二個參數是負數時，表示位置，取到哪一位，不包括自己
print_r($output);
echo "<br>";
$output = array_slice($input,2,-1,true);//第三個參數爲true時，保留原有的鍵值
print_r($output);
echo "<br>";


/**結果
Array ( [0] => c [1] => d [2] => e )
Array ( [0] => d )
Array ( [0] => a [1] => b [2] => c )
Array ( [0] => c [1] => d )
Array ( [2] => c [3] => d )
*/

 



count
功能：返回數組元素個數，元素爲數組的算一個

<?php
$input = array("a","b","c",array("d","e"));
$count = count($input);
echo $count;
echo "<br>";
$input = array("a","b","c","d","e");
$count = count($input);
echo $count;
/**結果
4
5
*/

 



current
功能:獲取當前的指針指向元素

<?php
$array = array("foot","bike","car","plane");
$result = current($array);
echo $result."<br>";
next($array);//使指針指向下一個元素
$result = current($array);
echo $result."<br>";
prev($array);//使指針指向前一個元素
$result = current($array);
echo $result."<br>";
end($array);//使指針指向最後一個元素
$result = current($array);
echo $result."<br>";
/**結果
foot
bike
foot
plane
*/

 



in_array
功能：檢驗某值是否存在數組中，有返回True，沒有返回False

<?php
$os_list = array("Mac","NT","Irix","Linux");
if(in_array("Irix",$os_list)){
    echo "當前操做系統列表中存在Irix";
}else{
    echo "當前操做系統列表中不存在Irix";
}
echo "<br>";
if(in_array("mac",$os_list)){
    echo "當前操做系統列表中存在mac";
}else{
    echo "當前操做系統列表中不存在mac";
}
echo "<br>";

/**結果
當前操做系統列表中存在Irix
當前操做系統列表中不存在mac
*/

 


list
功能：將數組中的信息賦值給多個變量

<?php
$info = array("red","blue","green");
list($flag,$sky,$grassland) = $info;
echo "$flag,$sky,$grassland";
echo "<br>";
list($flag,,$grassland) = $info;
echo "$flag,$grassland";
echo "<br>";
list(,,$grassland) = $info;
echo "$grassland";
echo "<br>";
/**結果
red,blue,green
red,green
green
*/

 

shuffle
功能：打亂數組

<?php
$numbers = range(1,5);//生成一個隨機數組
print_r($numbers);
echo "<br/>";
shuffle($numbers);//打亂數組
print_r($numbers);
/**結果
Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 )
Array ( [0] => 4 [1] => 1 [2] => 5 [3] => 2 [4] => 3 )
*/

 




array_keys
功能：獲取數組的鍵名，第二個參數能夠指定獲取某個元素

<?php
$array = array(0=>100,"color"=>"red");
print_r(array_keys($array));
echo "<br>";
$array = array("blue","red","green","blue","blue");
print_r(array_keys($array,"blue"));
echo "<br>";
$array = array("color"=>array("blue","red","green"),"size"=>array("small","medium","large"));
print_r(array_keys($array));
echo "<br>";
/**結果
Array ( [0] => 0 [1] => color )
Array ( [0] => 0 [1] => 3 [2] => 4 )
Array ( [0] => color [1] => size )
*/

 



array_reverse
功能：獲取數組的反向

<?php
$input = array("php",3.0,array("green","red"));
$result = array_reverse($input); //打亂鍵名
$result_keyed = array_reverse($input,TRUE);//保留鍵名
print_r($result);
print_r($result_keyed);
/**結果
Array
(
    [0] => Array
        (
            [0] => green
            [1] => red
        )

    [1] => 3
    [2] => php
)
Array
(
    [2] => Array
        (
            [0] => green
            [1] => red
        )

    [1] => 3
    [0] => php
)

*/

 


arsort
功能：逆向排序，索引不變

<?php
$fruits = array(
    "a"=>"lemon",
    "b"=>"orange",
    "c"=>"banana",
    "d"=>"apple",
    );
arsort($fruits);//按照字符逆向排序或數字
foreach($fruits as $key=>$val){
    echo "$key = $val<br>";
}
/**結果
b = orange
a = lemon
c = banana
d = apple
*/

 



asort
功能：進行正向排序

<?php
$fruits = array(
    "a"=>"lemon",
    "b"=>"orange",
    "c"=>"banana",
    "d"=>"apple",
    );
arsort($fruits);//按照字符逆向排序或數字
foreach($fruits as $key=>$val){
    echo "$key = $val<br>";
}
echo "<p>";
asort($fruits);//按照字符正向排序或數字
foreach($fruits as $key=>$val){
    echo "$key = $val<br>";
}
/**結果
b = orange
a = lemon
c = banana
d = apple

d = apple
c = banana
a = lemon
b = orange
*/

 



krsort
功能：按照鍵名進行逆向排序

<?php
$fruits = array(
    "a"=>"lemon",
    "b"=>"orange",
    "c"=>"banana",
    "d"=>"apple",
    );
krsort($fruits);//按照鍵名逆向排序或數字
foreach($fruits as $key=>$val){
    echo "$key = $val<br>";
}

/**結果
d = apple
c = banana
b = orange
a = lemon
*/

 


ksort
功能：按照鍵名進行正向排序

<?php
$fruits = array(
    "a"=>"lemon",
    "b"=>"orange",
    "c"=>"banana",
    "d"=>"apple",
    );
ksort($fruits);//按照鍵名正向排序或數字
foreach($fruits as $key=>$val){
    echo "$key = $val<br>";
}

/**結果
a = lemon
b = orange
c = banana
d = apple
*/

 


rsort
功能：按照值進行逆向排序，鍵名改變

<?php
$fruits = array(
    "a"=>"lemon",
    "b"=>"orange",
    "c"=>"banana",
    "d"=>"apple",
    );
rsort($fruits);//按照值進行逆向排序或數字，鍵名改變
foreach($fruits as $key=>$val){
    echo "$key = $val<br>";
}

/**結果
0 = orange
1 = lemon
2 = banana
3 = apple
*/

 



sort
功能：按照值進行正向排序，鍵名改變

<?php
$fruits = array(
    "a"=>"lemon",
    "b"=>"orange",
    "c"=>"banana",
    "d"=>"apple",
    );
sort($fruits);//按照值進行逆向排序或數字，鍵名改變
foreach($fruits as $key=>$val){
    echo "$key = $val<br>";
}

/**結果
0 = apple
1 = banana
2 = lemon
3 = orange
*/
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