Php array, modification, traversal, function, etc. _ PHP Tutorial

Php array, modification, traversal, and functions. Php array format: ①, numeric array form: array (v1, v2, v3, v4 ,.....) array (value 1, value 2, value 3,) ②, associated array form: array (k1v1, k2v2, k3v3 ,.......) array (key-1 php array format:

①, Numerical array

Format: array (v1, v2, v3, v4 ,.....)

Array (value 1, value 2, value 3 ,......)

② Join an array

Format: array (k1 => v1, k2 => v2, k3 => v3 ,.......)

Array (key 1 => value 1, key 2 => value 2, key 3 => value 3 ,......)

③ Multi-dimensional data

$ Arr_arr = array (4567, 77.7, 99,100), "aa", "bb", cc );

Data Display:

Print_r ()

Var_dump () (contains the type, length, and other information)

$ Arr = array (1, 2, 3, 4, 5 );

Print_r ($ arr );

Echo"
";

Var_dump ($ arr );

The result is:

Array ([0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5)

Array (5) {[0] => int (1) [1] => int (2) [2] => int (3) [3] => int (4) [4] => int (5 )}

Array traversal foreach ():

$ Arr = array (1, 2, 3, 4, 5 );

Foreach ($ arr as $ k =>$ v ){

Echo "key => value is". $ k. "=>". $ v ."
";

}

Multi-dimensional array output:

$ Arr_arr = array (4567, 77.7, 99,100), "aa", "bb", cc );

Echo "var_dump multi-dimensional array
";

Var_dump ($ arr_arr );

Echo "print_r () multi-dimensional array
";

Print_r ($ arr_arr );

Display:

Var_dump multi-dimensional array

Array (4) {[0] => array (4) {[0] => int (4567) [1] => float (77.7) [2] => int (99) [3] => int (100)} [1] => string (2) "aa" [2] => string (2) "bb" [3] => string (2) "cc"} print_r () multi-dimensional array

Array ([0] => Array ([0] => 4567 [1] => 77.7 [2] => 99 [3] => 100) [1] => aa [2] => bb [3] => cc)

Array functions:

Delete function: unset ($ arr ['K']);

Value sorting: sort (), rsort () (reverse)

Key sorting: ksort (), krsort ()

Sum: array_sum ($ array)

Number: count () <----> sizeof ()

Search: in_array (value, $ array)

Array_search (value, $ array)

Look at the W3Cschool, paste a directory, and get familiar with the learning plan:

I. php Basics

PHP Basics

PHP Tutorial

PHP introduction

PHP installation

PHP syntax

PHP variables

PHP string

PHP operators

PHP If... Else

PHP Switch

PHP array

PHP loop

PHP functions

PHP form

PHP $ _ GET

PHP $ _ POST

2. php advanced

PHP advanced

PHP date

PHP Include

PHP files

PHP file Upload

PHP Cookies

PHP Sessions

Php e-mail

PHP secure E-mail

PHP Error

PHP Exception

PHP Filter

III. php database

PHP database

MySQL introduction

MySQL Connect

MySQL Create

MySQL Insert

MySQL Selecth

MySQL Where

MySQL Order

MySQL Update

MySQL Delete

PHP ODBC

4. php and xml

PHP XML

XML Expat Parser

XML DOM

XML SimpleXML

V. php and ajax

PHP and AJAX

AJAX introduction

XMLHttpRequest

AJAX Suggest

AJAX XML

AJAX Database

AJAX responseXML

AJAX Live Search

Ajax rss Reader

AJAX Poll

①, The value array is like: array (v1, v2, v3, v4 ,.....) array (value 1, value 2, value 3,) ②, associated array form: array (k1 = v1, k2 = v2, k3 = v3 ,.......) array (key 1 = value...