PHP array, modification, traversal, function, etc.

PHP array, modification, traversal, function, etc._PHP tutorial

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Release： 2016-07-14 10:08:46

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The form of php array:

①, numerical array

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

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

②, associative array

The shape is: array(k1=>v1,k2=>v2,k3=>v3,....)

array(key1=>value1, key2=>value2, key3=>value3,…)

③, multi-dimensional data

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

Data display:

print_r()

var_dump() (contains 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."
";

}

Output of multidimensional array:

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

echo "var_dump multidimensional array
";

var_dump($arr_arr);

echo "print_r() multidimensional array
";

print_r($arr_arr);

Display:

var_dump multidimensional 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() multidimensional array

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

Array function:

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

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

Key sorting: ksort(), krsort()

Sum: array_sum($array)

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

Find: in_array(value,$array)

array_search(value,$array)

Hey, let’s take a look at W3Cschool first, post a table of contents, start a study plan, and get familiar with it:

1, PHP basics

PHP Basics

PHP Tutorial

Introduction to PHP

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 File

PHP file upload

PHP Cookies

PHP Sessions

PHP E-mail

PHP Secure E-mail

PHP Error

PHP Exception

PHP Filter

Three, php database

PHP Database

Introduction to MySQL

MySQL Connect

MySQL Create

MySQL Insert

MySQL Sele

MySQL Where

MySQL Order By

MySQL Update

MySQL Delete

PHP ODBC

Four, php and xml

PHP XML

XML Expat Parser

XML DOM

XML SimpleXML

Five, php and ajax

PHP and AJAX

Introduction to AJAX

XMLHttpRequest

AJAX Suggest

AJAX XML

AJAX Database

AJAX responseXML

AJAX Live Search

AJAX RSS Reader

AJAX Poll