• php常用函数


    array_combine
    功能:用一个数组的值作为新数组的键名,另一个数组的值作为新数组的值
    案例:

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


    array_chunk
    功能:拆分数组成多个数组

    <?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>";
    /**结果
    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:统计数组中值出现的次数

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



    array_diff
    功能:第一个数组中去掉第二个数组中有的数据,返回剩下的内容作为结果

    <?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);//数组1中去掉数组2中剩下的
    print_r($result2);//数组2中去掉数组1中剩下的
    echo "</pre>";
    /**结果
    Array
    (
        [b] => blue
        [2] => e
    )
    Array
    (
        [3] => f
    )
    */

    array_map
    功能:将回调函数执行到数组中

    <?php
    //定义回调函数
    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>";
    
    /**结果
    Array
    (
        [0] => 1
        [1] => 8
        [2] => 27
        [3] => 64
        [4] => 125
    )
    */



    array_merge
    功能:合并一个或多个数组
    说明:如果后面有键名相同的会覆盖掉前面的内容,键名为数字的会添加到后面

    <?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>";
    
    /**结果
    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:剔除数组最后一个元素,返回被剔除的元素内容

    <?php
    $stack = array("orange","banana","apple","1");
    $last = array_pop($stack);
    echo "<pre>";
    print_r($stack);
    print_r($last);
    echo "</pre>";
    
    /**结果
    Array
    (
        [0] => orange
        [1] => banana
        [2] => apple
    )
    1
    */



    array_push
    功能:将一个多个单元压入数组末尾,返回之后的数组个数

    <?php
    $stack = array("orange","banana");
    $count = array_push($stack,"apple","red","blue");
    echo "<pre>";
    print_r($stack);
    print_r($count);
    echo "</pre>";
    
    /**结果
    Array
    (
        [0] => orange
        [1] => banana
        [2] => apple
        [3] => red
        [4] => blue
    )
    5
    */



    array_rand
    功能:获取随机的键名

    <?php
    $input = array("orange","banana","apple","red","blue");
    $rand = array_rand($input,2);;
    print_r($rand);
    $rand = array_rand($input,3);
    print_r($rand);
    
    /**结果
    Array
    (
        [0] => 1
        [1] => 4
    )
    Array
    (
        [0] => 0
        [1] => 1
        [2] => 3
    )
    
    */



    array_search
    功能:查询数组中的内容,返回键值,如果有多个匹配,返回第一个匹配的内容

    <?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>";
    /**结果
    blue
    red
    */


    array_shift
    功能:移除开头的元素,与array_pop相反

    <?php
    $fruit = array("milk","orange","banana","apple");
    $top = array_shift($fruit);
    print_r($top);
    echo "<br>";
    print_r($fruit);
    
    /**结果
    milk
    Array ( [0] => orange [1] => banana [2] => apple )
    */

    array_unique
    功能:去除数组重复的元素,保留第一个出现的,包括键名和值

    <?php
    $input = array("a"=>"green","red","b"=>"green","blue","c"=>"red");
    $result = array_unique($input);
    print_r($result);
    echo "<br>";
    print_r($input);
    
    /**结果
    Array ( [a] => green [0] => red [1] => blue )
    Array ( [a] => green [0] => red [b] => green [1] => blue [c] => red )
    */



    array_slice

    功能:从数组中取出部分元素
    <?php
    $input = array("a","b","c","d","e");
    $output = array_slice($input,2);//第二个参数没有时,表示取到最后一个元素
    print_r($output);
    echo "<br>";
    $output = array_slice($input,-2,1);//第二个参数是正数时,表示个数;倒数第一个是-1,倒数第二个是-2
    print_r($output);
    echo "<br>";
    $output = array_slice($input,0,3);
    print_r($output);
    echo "<br>";
    $output = array_slice($input,2,-1);//第二个参数是负数时,表示位置,取到哪一位,不包括本身
    print_r($output);
    echo "<br>";
    $output = array_slice($input,2,-1,true);//第三个参数为true时,保留原有的键值
    print_r($output);
    echo "<br>";
    
    
    /**结果
    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:返回数组元素个数,元素为数组的算一个

    <?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;
    /**结果
    4
    5
    */



    current
    功能:获取当前的指针指向元素

    <?php
    $array = array("foot","bike","car","plane");
    $result = current($array);
    echo $result."<br>";
    next($array);//使指针指向下一个元素
    $result = current($array);
    echo $result."<br>";
    prev($array);//使指针指向前一个元素
    $result = current($array);
    echo $result."<br>";
    end($array);//使指针指向最后一个元素
    $result = current($array);
    echo $result."<br>";
    /**结果
    foot
    bike
    foot
    plane
    */



    in_array
    功能:检验某值是否存在数组中,有返回True,没有返回False

    <?php
    $os_list = array("Mac","NT","Irix","Linux");
    if(in_array("Irix",$os_list)){
        echo "当前操作系统列表中存在Irix";
    }else{
        echo "当前操作系统列表中不存在Irix";
    }
    echo "<br>";
    if(in_array("mac",$os_list)){
        echo "当前操作系统列表中存在mac";
    }else{
        echo "当前操作系统列表中不存在mac";
    }
    echo "<br>";
    
    /**结果
    当前操作系统列表中存在Irix
    当前操作系统列表中不存在mac
    */


    list
    功能:将数组中的信息赋值给多个变量

    <?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>";
    /**结果
    red,blue,green
    red,green
    green
    */

    shuffle
    功能:打乱数组

    <?php
    $numbers = range(1,5);//生成一个随机数组
    print_r($numbers);
    echo "<br/>";
    shuffle($numbers);//打乱数组
    print_r($numbers);
    /**结果
    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:获取数组的键名,第二个参数可以指定获取某个元素

    <?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>";
    /**结果
    Array ( [0] => 0 [1] => color )
    Array ( [0] => 0 [1] => 3 [2] => 4 )
    Array ( [0] => color [1] => size )
    */



    array_reverse
    功能:获取数组的反向

    <?php
    $input = array("php",3.0,array("green","red"));
    $result = array_reverse($input); //打乱键名
    $result_keyed = array_reverse($input,TRUE);//保留键名
    print_r($result);
    print_r($result_keyed);
    /**结果
    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,索引不变

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



    asort
    功能:进行正向排序

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



    krsort
    功能:按照键名进行逆向排序

    <?php
    $fruits = array(
        "a"=>"lemon",
        "b"=>"orange",
        "c"=>"banana",
        "d"=>"apple",
        );
    krsort($fruits);//按照键名逆向排序或数字
    foreach($fruits as $key=>$val){
        echo "$key = $val<br>";
    }
    
    /**结果
    d = apple
    c = banana
    b = orange
    a = lemon
    */


    ksort
    功能:按照键名进行正向排序

    <?php
    $fruits = array(
        "a"=>"lemon",
        "b"=>"orange",
        "c"=>"banana",
        "d"=>"apple",
        );
    ksort($fruits);//按照键名正向排序或数字
    foreach($fruits as $key=>$val){
        echo "$key = $val<br>";
    }
    
    /**结果
    a = lemon
    b = orange
    c = banana
    d = apple
    */


    rsort
    功能:按照值进行逆向排序,键名改变

    <?php
    $fruits = array(
        "a"=>"lemon",
        "b"=>"orange",
        "c"=>"banana",
        "d"=>"apple",
        );
    rsort($fruits);//按照值进行逆向排序或数字,键名改变
    foreach($fruits as $key=>$val){
        echo "$key = $val<br>";
    }
    
    /**结果
    0 = orange
    1 = lemon
    2 = banana
    3 = apple
    */



    sort
    功能:按照值进行正向排序,键名改变

    <?php
    $fruits = array(
        "a"=>"lemon",
        "b"=>"orange",
        "c"=>"banana",
        "d"=>"apple",
        );
    sort($fruits);//按照值进行逆向排序或数字,键名改变
    foreach($fruits as $key=>$val){
        echo "$key = $val<br>";
    }
    
    /**结果
    0 = apple
    1 = banana
    2 = lemon
    3 = orange
    */
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  • 原文地址:https://www.cnblogs.com/jiqing9006/p/3095314.html
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