PHP中常用的數(shù)組操作方法筆記整理

<?php 
 $array = array(); 
 $array["key"] = "values"; 
?> 

<?php
 //array數(shù)組
 $users = array('phone','computer','dos','linux');
 echo $users;//只會打印出數(shù)據(jù)類型Array
 print_r($users);//Array ( [0] => phone [1] => computer [2] => dos [3] => linux )

 $numbers = range(1,5);//創(chuàng)建一個包含指定范圍的數(shù)組
 print_r($numbers);//Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 )
 print_r(true);//1
 var_dump(false);//bool(false)

//print_r可以把字符串和數(shù)字簡單地打印出來，數(shù)組會以Array開頭并已鍵值形式表示，print_r

<?php

 //創(chuàng)建自定義鍵的數(shù)組
 $ceo = array('apple'=>'jobs','microsoft'=>'Nadella','Larry Page','Eric');
 //如果不去聲明元素的key,它會從零開始
 print_r($ceo);//Array ( [apple] => jobs [microsoft] => Nadella [0] => Larry Page [1] => Eric )

 echo $ceo['apple'];//jobs

 //php5.4起的用法
 $array = [
 "foo" => "bar",
 "bar" => "foo",
 ];

 print_r($array);//Array ( [foo] => bar [bar] => foo ) 

?> 

<?php
 //通過為數(shù)組元素賦值來創(chuàng)建數(shù)組
 $ages['trigkit4'] = 22;
 echo $ages.'<br/>';//Array
 //因為相關數(shù)組的索引不是數(shù)字，所以無法通過for循環(huán)來進行遍歷操作，只能通過foreach循環(huán)或list()和each()結構

 //each的使用
 //each返回數(shù)組中當前的鍵/值對并將數(shù)組指針向前移動一步
 $users = array('trigkit4'=>22,'mike'=>20,'john'=>30);
 //print_r(each($users));//Array ( [1] => 22 [value] => 22 [0] => trigkit4 [key] => trigkit4 )

 //相當于：$a = array([0]=>trigkit4,[1]=>22,[value]=>22,[key]=>trigkit4);
 $a = each($users);//each把原來的數(shù)組的第一個元素拿出來包裝成新數(shù)組后賦值給$a
 echo $a[0];//trigkit4

 //!!表示將真實存在的數(shù)據(jù)轉換成布爾值
 echo !!each($users);//1

?> 

<?php

 $a = ['2','abc','def'];
 list($var1,$var2) = $a;
 echo $var1.'<br/>';//2
 echo $var2;//abc

 $a = ['name'=>'trigkit4','age'=>22,'0'=>'boy'];
 //list只認識key為數(shù)字的索引
 list($var1,$var2) = $a;

 echo $var1;//boy

?>

<?php
 $numbers = array('100','2');
 sort($numbers,SORT_STRING);//按字符串排序，字符串只比較第一位大小
 print_r($numbers);//Array ( [0] => 100 [1] => 2 )

 $arr = array('trigkit4','banner','10');
 sort($arr,SORT_STRING);
 print_r($arr);//Array ( [0] => 10 [1] => banner [2] => trigkit4 )

 shuffle($arr);
 print_r($arr);//隨機排序

 $array = array('a','b','c','d','0','1');
 array_reverse($array);
 print_r($array);//原數(shù)組的反向排序。 Array ( [0] => a [1] => b [2] => c [3] => d [4] => 0 [5] => 1 )


 //數(shù)組的拷貝
 $arr1 = array( '10' , 2);
 $arr2 = &$arr1 ;
 $arr2 [] = 4 ; // $arr2 被改變了,$arr1仍然是array('10', 3)
 print_r($arr2);//Array ( [0] => 10 [1] => 2 [2] => 4 )

 //asort的使用
 $arr3 = & $arr1 ;//現(xiàn)在arr1和arr3是一樣的
 $arr3 [] = '3' ;
 asort($arr3);//對數(shù)組進行排序并保留原始關系
 print_r($arr3);// Array ( [1] => 2 [2] => 3 [0] => 10 )

 //ksort的使用
 $fruits = array('c'=>'banana','a'=>'apple','d'=>'orange');
 ksort($fruits);
 print_r($fruits);//Array ( [a] => apple [c] => banana [d] => orange )

 //unshift的使用
 array_unshift($array,'z');//開頭處添加一元素
 print_r($array);//Array ( [0] => z [1] => a [2] => b [3] => c [4] => d [5] => 0 [6] => 1 ) 

 //current(pos)的使用
 echo current($array);//z;獲取當前數(shù)組中的當前單元

 //next的使用
 echo next($array);//a;將數(shù)組中的內部指針向前移動一位

 //reset的使用
 echo reset($array);//z;將數(shù)組內部指針指向第一個單元

 //prev的使用
 echo next($array);//a;
 echo prev($array);//z;倒回一位

 //sizeof的使用
 echo sizeof($array);//7；統(tǒng)計數(shù)組元素的個數(shù)

 //array_count_values
 $num = array(10,20,30,10,20,1,0,10);//統(tǒng)計數(shù)組元素出現(xiàn)的次數(shù)
 print_r(array_count_values($num));//Array ( [10] => 3 [20] => 2 [30] => 1 [1] => 1 [0] => 1 ) 

?> 

<?php
 $value = range(0,120,10);
 for($i=0;$i<count($value);$i++){
 print_r($value[$i].' ');//0 10 20 30 40 50 60 70 80 90 100 110 120 
 }
?>

<?php
 //array_pad函數(shù)，數(shù)組數(shù)組首尾選擇性追加
 $num = array(1=>10,2=>20,3=>30);
 $num = array_pad($num,4,40);
 print_r($num);//Array ( [0] => 10 [1] => 20 [2] => 30 [3] => 40 )

 $num = array_pad($num,-5,50);//array_pad(array,size,value)
 print_r($num);//Array ( [0] => 50 [1] => 10 [2] => 20 [3] => 30 [4] => 40 ) 
?>

 <?php
 //unset()的使用
 $num = array_fill(0,5,rand(1,10));//rand(min,max)
 print_r($num);//Array ( [0] => 8 [1] => 8 [2] => 8 [3] => 8 [4] => 8 ) 
 echo '<br/>';

 unset($num[3]);
 print_r($num);//Array ( [0] => 8 [1] => 8 [2] => 8 [4] => 8 ) 
?>

<?php
 //array_fill()的使用
 $num = range('a','e');
 $arrayFilled = array_fill(1,2,$num);//array_fill(start,number,value)
 echo '<pre>';

 print_r($arrayFilled);

?>

<?PHP
 $number = array(1,2,3,4,5);
 $array = array("I","Am","A","PHP","er");
 $newArray = array_combine($number,$array);
 print_r($newArray);//Array ( [1] => I [2] => Am [3] => A [4] => PHP [5] => er ) 
?> 

<?php
 $color = array("red", "green", "blue", "yellow");
 count ($color); //得到4
 array_splice($color,1,1); //刪除第二個元素
 print_r(count ($color)); //3
 echo $color[2]; //yellow
 echo $color[1]; //blue
?> 

<?php
 $color=array("red", "green", "blue", "yellow","blue","green");
 $result = array_unique($color);
 print_r($result);//Array ( [0] => red [1] => green [2] => blue [3] => yellow ) 
?> 

<?PHP
 $array = array("red","blue","red","Black");
 print_r($array);
 echo "<br />";
 $array = array_flip($array);//
 print_r($array);//Array ( [red] => 2 [blue] => 1 [Black] => 3 ) 
?> 

<meta charset="utf-8">
<?php
 $array = array("red","blue","red","Black");
 $result=array_search("red",$array)//array_search(value,array,strict)
 if(($result === NULL)){
 echo "不存在數(shù)值red";
 }else{
 echo "存在數(shù)值 $result";//存在數(shù)值 0 
 }
?>