PHP Regular Expressions and arrays

<?php
Regular expressions
Slash stands for delimiter/^$/
/*
$str = "abcde123fg456h";
$reg = "/\d/";
Echo preg_replace ($reg, "#", $str);//replace the string str with the regular expression Reg #
Var_dump (Preg_split ($reg, $str)); Splitting a string str by regular expression

$arr =array ();
Preg_match ($reg, $str, $arr);//Match the first data in a string that satisfies a regular expression
Var_dump ($arr);

Preg_match_all ($reg, $str, $arr);//Match all data in a string that satisfies a regular expression
Var_dump ($arr);
*/




Array
Defined
/*
$arr =array (1,2,3,4,5);//1. Defining an array 1
2. Assignment definitions
$arr [1]=5;
$arr [2]=6;
Var_dump ($arr);
*/

Array classification
1. Indexed arrays
/* $arr =array (1,2,3,4,5);
echo $arr [0];*/
2. Associative arrays
/* $arr =array ("code" =>5, "name" =>10);
echo $arr ["Name"];*/
PHP Array Features: Can store any type of data, the length can vary

$arr =array ("AA", "BB", 5, "CC", 10);
$arr =array ("A" =>10, "B" =>20, "c" = "Hello", "D" >=30);//associative arrays cannot be traversed with a for loop
For loop traversal
/*for ($i =0; $i <count ($arr); $i + +)
{
echo $arr [$i]. " <br> ";
}*/

2.foreach traversal
/* $arr =array ("A" =>10, "B" =>20, "c" = "Hello", "D" =>30);//associative arrays cannot be traversed with a for loop
foreach ($arr as $value)
{
echo $value. " <br> ";
}

foreach ($arr as $key = $value)
{
echo $key. " --". $value." <br> ";
}*/

3.each () function
/*
$arr =array ("A" =>10, "B" =>20, "c" = "Hello", "D" =>30);
Var_dump (each ($arr));//returns the key and value of the element inside the array
Var_dump (each ($arr));//Take the value down one at a time to point to the next value

4.list () function
$arr =array ("AA", "BB", 5, "CC", 10);
List ($a, $b, $c, $d) = $arr;//assigns the value of the array arr to a variable in the list function; list can be written less, not more
Echo $d;
*/

5.each () and list () iterate through the array.
/*
$arr =array ("AA", "BB", 5, "CC", 10);
while (list ($key, $value) =each ($arr))
{
echo "{$key}--{$value}<br>";
}*/

6. Pointers

$arr =array ("AA", "BB", 5, "CC", 10);
Var_dump (current ($arr)); Value that points to the position of the current pointer
echo Key ($arr);//Take the current pointer to the position of the key value
Next ($arr); Adjust the pointer to
echo Key ($arr);
Prev ($arr); Raise the pointer to
End ($arr); Move the pointer to the last
Rest ($arr); Reset the pointer to the first


$arr =array ("AA", "BB", 5, "CC", 10);
/*while (Next ($arr))
{
echo Key ($arr). " --". Current ($arr)." <br> ";
}*/


/*do
{
echo Key ($arr). " --". Current ($arr)." <br> ";
}
while (Next ($arr)) */

/*
$arr =array ("AA", "BB", 5,5, "CC", 10);
Var_dump (In_array ("AB", $arr));//Determine if there is a value in the array
Var_dump (Array_reverse ($arr));//Flip Array
echo count ($arr); Number of arrays
$attr =array_unique ($arr); Removes duplicates within the array
unset ($attr [0]); Delete an array
Var_dump (Array_values ($attr));//re-index

$attr =array (1,2,3,4,5);
Array_merge ($arr, $attr);//merge arrays
Array_push ($arr, "DD"); Add an element to an array
Var_dump ($arr);
*/


Two-dimensional arrays
/*
$attr =array (
Array (+/-),
Array (4,5,6),
Array (7,8,9)
);
Var_dump ($ATTR);
*/

Example
$attr =array (
Array (' n001 ', ' Han '),
Array (' n002 ', ' Miao '),
Array (' n003 ', ' hui '),
Array (' n004 ', ' Uighur '),
);
Displays the contents of the array in the drop-down list
echo "<select>";
foreach ($attr as $value)
{
echo "<option value= ' {$value [0]} ' >{$value [1]}</option>";
}
echo "</select>";

Display the contents of the array in a table
$attr =array (
Array (' P001 ', ' Zhang San ', ' Male ', ' Han '),
Array (' P002 ', ' John Doe ', ' female ', ' hui '),
Array (' P003 ', ' Harry ', ' Male ', ' Miao '),
Array (' p004 ', ' Zhao Liu ', ' female ', ' Uighur '),
);
echo "<table width= ' 800px ' border= ' 1px ' cellspacing= ' 0 ' cellpadding= ' 0 ' align= ' center ' >";
echo "<tr><td> number </td><td> name </td><td> Gender </td><td> National </td> </tr> ";
for ($i =0; $i <count ($attr); $i + +)
{
echo "<tr><td>{$attr [$i][0]}</td><td>{$attr [$i][1]}</td><td>{$attr [$i][2]} </td><td>{$attr [$i][3]}</td></tr>];
}
echo "</table>";

PHP Regular Expressions and arrays