php-An array of small notes (ii)

1.count ()

1<?PHP2     /*count () function counts the number of elements in an array*/  3     $student=Array(4         Array(' name ' = ' Wang ', ' age ' =>18),5         Array(' name ' = ' Lee ', ' age ' =>20)6         );7 8     Echo Count($student);//non-recursive 29     Echo Count($student, 1);//Recursive 6Ten?>

2.array_count_values () and Array_unique ()

1<?PHP2     /*array_count_values () counts the number of repetitions in the array, returns an array, the key represents the value name, and the value is the number of repetitions*/3     $a=Array(1,1,1, ' hello ', ' hello ', ' Mike '));4     Print_r(array_count_values($a));//Array ([1] = 3 [Hello] = 2 [Mike] + 1)5 6 7     /*array_unique () removes duplicate values from the array, preserving only the first occurrence of the key name*/8     Print_r(Array_unique($a));//Array ([0] = 1 [3] = = Hello [5] = Mike)9?>

3.array_filter ()

1<?PHP2     /*Array_filter () passes in a function name string, which is filtered by an array of functions, returns True to be preserved, otherwise deleted*/ 3 4     $a=Array(1,2,3,4,5,6,7,8,9,10);5 6     functionMyfun ($i){7         if($i%2==0)return true;8         Else return false;9     }Ten  One     Print_r(Array_filter($a, ' Myfun ')); A?>

4.array_walk ()

1<?PHP2     /*Array_walk ()*/3     /*The first argument is a reference to an array*/4     /*The second parameter is a callback function, in which array_walk () sequentially passes each value and key as the first second parameter in a*/5     /*if the callback function also has a third parameter, you can pass in the third parameter of the Array_walk ()*/6 7     functionTest$value,$key,$i)8     {9         Echo"Key:".$key.$i.$value." <br> ";Ten     } One  A     $a=Array(1,2,3,4,5,6); -     Array_walk($a, ' Test ', ' relation to value: '); -      the?>

5.sort () and Asort ()

1<?PHP2     /*sort () passes in a reference to an array, sorting the array in ascending order of values*/3     4     $a=Array(3,7,9,1,2,3,10);5     Sort($a);6     Print_r($a);//Array ([0] = 1 [1] = 2 [2] = 3 [3] = 3 [4] = 7 [5] = 9 [6] = +)7 8     /*If the letter is in ascending order by the ASCLL value of the letter*/9     $b=Array(' arr ', ' cada ', ' a ', ' FSFAFSJ ');Ten     Sort($b); One     Print_r($b);//Array ([0] = a [1] = arr [2] = = Cada [3] = FSFAFSJ) A  -     /*the Rsort () function is opposite to sort ()*/ -     Rsort($a); the     Print_r($a);//Array ([0] = [1] = 9 [2] = 7 [3] = 3 [4] = 3 [5] = 2 [6] = 1) -  -     Rsort($b); -     Print_r($b);//Array ([0] = FSFAFSJ [1] = Cada [2] = arr [3] = = a) +  -  +     /*Asort () is similar to sort (), but retains the original key-value relationship*/ A  at     Asort($a);Print_r($a);//Array ([6] = 1 [5] = 2 [4] = 3 [3] = 3 [2] = 7 [1] = 9 [0] = +) -?>

6.ksort ()

1 <? PHP 2     /* the Ksort () function is arranged in ascending order based on the key array */ 3     $a=array(3=> ' three ',1=> ' one ',7=> ' seven ',2=> ' both '); 4     Ksort ($a); 5     Print_r ($a); //  6 ?>

7. Custom sorting

1<?PHP2     /*the Usort () function can pass in a function name string, which determines how it is arranged*/3 4     $a=Array(' Asasas ', ' asgsudg ', ' asgsqyg ', ' aaaaaaaaaaaa ', ' Sada ');5 6     functionLen$a,$b)7     {8         if(strlen($a) >strlen($b))return1;9         Else if(strlen($a) <strlen($b))return-1;Ten         Else return0; One     } A     Usort($a, ' Len '); -     Print_r($a); -  the     /*Similarly, you can also use Uasort () and Uksort ()*/ -?>

php-An array of small notes (ii)