Php array declaration, traversal, array global variables

Welcome to the Linux community forum and interact with 2 million technical staff to enter foreach ($ useras $ key $ val) $ val $ key is a custom variable {echo $ key .. $ val.br;} foreach traverses multi-dimensional arrays $ infoarray (userarray ($ user [0] array (1, zansan, 10, nan), $ user

Welcome to the Linux community forum and interact with the 2 million technical staff> enter foreach ($ user as $ key = $ val) // $ val $ key are all custom variables {echo $ key. "= ". $ val. "br";} // foreach traverse multi-dimensional arrays $ info = array ("user" = array (// $ user [0] array (1, "zansan", 10, "nan"), // $ user

Welcome to the Linux community forum and interact with 2 million technicians>

Foreach ($ user as $ key => $ val) // $ val $ key is a custom variable

{

Echo $ key. "=====>". $ val ."
";

}

// Foreach traverses multi-dimensional arrays

$ Info = array (

"User" => array (

// $ User [0]

Array (1, "zansan", 10, "nan "),

// $ User [1] [1]

Array (2, "lisi", 20, "nv"), // $ user [1]

// $ User [2]

Array (3, "wangwu", 30, "nan ")

),

"Score" => array (

Array (1,100, 90, 80 ),

Array (2, 99, 88, 11 ),

Array (3, 10, 50, 88)

),

"Connect" => array (

Array (1, '123', 'aaa @ bbb.com '),

Array (2, '123', 'bbb @ ccc.com '),

Array (3, '123', 'ccc @ ddd.com ')

)

);

Foreach ($ info as $ tableName => $ table)

{

Echo'

Echo'

Foreach ($ table as $ row)

{

Echo'

Foreach ($ row as $ col)

{

Echo'

}

Echo'

}

Echo'

'; '; '; '; ';

'. $ TableName .'

'. $ Col .'

';

}

// Use of each ()

$ User = array ("id" => 1, "name" => "zhangsan", "age" => 10, "sex" => "nan ");

$ A = each ($ user); // Array ([1] => 1 [value] => 1 [0] => id [key] => id) the default value is the value of the first element.

Print_r ($ );

$ B = each ($ user );

Print_r ($ B); // Array ([1] => zhangsan [value] => zhangsan [0] => name [key] => name) each time, traverse one

$ C = each ($ user );

Print_r ($ c); // Array ([1] => 10 [value] => 10 [0] => age [key] => age)

$ D = each ($ user );

Print_r ($ d); // Array ([1] => nan [value] => nan [0] => sex [key] => sex)

$ E = each ($ user );

Var_dump ($ e); // bool (false) value returned when no element exists

// Each () and while Traversal

$ User = array ("id" => 1, "name" => "zhangsan", "age" => 10, "sex" => "nan ");

While ($ arr = each ($ user ))

{

// Echo $ arr [0]. "===>". $ arr [1]."
"; // Display the key (subscript) and value through 0, 1

Echo $ arr ["key"]. "==>". $ arr ["value"]."
"; // Key and value are used to display the key value

}

// Use the list () function

List ($ name, $ age, $ sex) = array ("zhangsan", 10, "nnnnn ");

Echo $ name ."
";

Echo $ age ."
";

Echo $ sex ."
";

// ANOTHER METHOD

List (, $ sex) = array ("zhangsan", 10, "nnnnn ");

Echo $ sex ."
"; // Only convert gender to variable

// Ip judgment

$ Ip = "192.168.1.128 ";

List (, $ d) = explode (".", $ ip); // explode is separated by. And an array is returned.

Echo $ d; // retrieve 128

// List () can only receive indexed arrays.

$ User = array ("id" => 1, "name" => "zhangsan", "age" => 10, "sex" => "nan ");

List ($ key, $ value) = each ($ user); // Array ([1] => 1 [0] => id) assign values to the parameters in the list according to the order of the index, so the values are 0 and 1.

Echo $ key. "--->". $ value;

// While list () each () Combination

$ User = array ("id" => 1, "name" => "zhangsan", "age" => 10, "sex" => "nan ");

While (list ($ key, $ value) = each ($ user ))

{

Echo $ key. "--->". $ value ."
";

}

// The solution is to display only once for multiple cycles

// Use the internal pointer control function of the array

// Next (array); move the array pointer to the next

// Prev (array); move the array pointer to the previous one

// Reset (array); move the array pointer to the first one (reset)

// End (array); the array pointer moves to the last one

// Current (array); obtains the value of the current element. The element pointed to by the index group pointer when the current element is present.

// Key (array); obtains the key value (subscript) of the current element)

$ User = array ("id" => 1, "name" => "zhangsan", "age" => 10, "sex" => "nan ");

While (list ($ key, $ value) = each ($ user ))

{

Echo $ key. "--->". $ value ."
";

}

// Here, move the array pointer to the first loop below to output

// Reset ($ user)

While (list ($ key, $ value) = each ($ user) // The loop jumps out directly because each () returns false to the last one.

{

Echo $ key. "--->". $ value ."
";

}

While (list ($ key, $ value) = each ($ user) // The loop jumps out directly because each () returns false to the last one.

{

Echo $ key. "--->". $ value ."
";

}

Echo current ($ user). "====>". key ($ user );

?>

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