PHP array learning

For Web programming, the most important thing is to access and read/write data. There may be many storage methods, such as strings, arrays, and files. I learned arrays today, which is an important method in PHP Data applications. PHP has a large number of array functions. The following is a summary of my learning, so that we can easily learn SyntaxHighlighter. all () in the future ();

For Web programming, the most important thing is to access and read/write data. There may be many storage methods, such as strings, arrays, and files. I learned arrays today, which is an important method in PHP Data applications. PHP has a large number of array functions. The following is a summary of my learning, so that you can easily identify them later ......
 

I. array definition:
The array definition uses the array () method to define an empty array:

$ Number = array (1, 3, 5, 7, 9 );

// Define an empty array

$ Result = array ();

$ Color = array ("red", "blue", "green ");

// Custom key value

$ Language = (1 => "English", 3 => "Chinese", 5 => "Franch ");

// Define a two-dimensional array

$ Two = array (

"Color" => array ("red", "blue"), // end with a comma

"Week" => array ("Monday", "Friday") // The last sentence contains no punctuation );

?>
2. create an array:
Create the functions included in the array: compact (),

1. compact () function -- convert one or more variables (including arrays) to an array:
Array compact (mixed $ varname [, mixed $...])

$ Number = "1, 3, 5, 7, 9 ";

$ String = "Im PHPer ";

$ Array = array ("And", "You? ");

$ NewArray = compact ("number", "string", "array ");

Print_r ($ newArray );

?>

The compact () function is used to convert two or more variables to an array. of course, it also contains array variables. The parameter is the variable name, not the $ full name.

The opposite function is extract (). as the name suggests, it is to convert an array into a single string. The key value is used as the string name, and the array value is used as the string value.

Running result:

Array ([number] => 1, 3, 5, 7, 9 [string] => Im PHPer [array] => Array ([0] => And [1] => You? ))

2. array_combine () -- combines two arrays into an array, one as the key value and the other as the value:
Array array_combine (array $ keys, array $ values)

$ Number = array ("1", "3", "5", "7", "9 ");

$ Array = array ("I", "Am", "A", "PHP", "er ");

$ NewArray = array_combine ($ number, $ array );

Print_r ($ newArray );

?>

No more about the array_combine function.

Running result:

Array ([1] => I [3] => Am [5] => A [7] => PHP [9] => er)

3. range () function -- create an array of the specified range:
Let's just move on to the instance directly --

$ Array1 = range (0,100, 10 );

// 0 indicates the start value, 100 indicates the end value, and 10 indicates the step value (the default step value is 1 ).

Print_r ($ array1); echo"
";

$ Array2 = range ("A", "Z ");

Print_r ($ array2 );

Echo"
";

$ Array3 = range ("z", "a"); print_r ($ array3 );

?>

The default step value of the range () function is 1!

Running result:

Array ([0] => 0 [1] => 10 [2] => 20 [3] => 30 [4] => 40 [5] => 50 [6] = & gt; 60 [7] = & gt; 70 [8] = & gt; 80 [9] = & gt; 90 [10] = & gt; 100) array ([0] => A [1] => B [2] => C [3] => D [4] => E [5] => F [6] => G [7] => H [8] => I [9] => J [10] => K [11] => L [12] => M [13] => N [14] => O [15] => P [16] => Q [17] => R [18] => S [19] => T [20] => U [21] => V [22] => W [23] => X [24] => Y [25] => Z) array ([0] => z [1] => y [2] => x [3] => w [4] => v [5] => u [6] => t [7] => s [8] => r [9] => q [10] => p [11] => o [12] => n [13] => m [14] => l [15] => k [16] => j [17] => I [18] => h [19] => g [20] => f [21] => e [22] => d [23] => c [24] => B [25] =>)

4. array_fill () function -- fill the array function:

$ Array = range (1, 10 );

$ Fillarray = range ("a", "d ");

$ ArrayFilled = array_fill (0, 5, $ fillarray );

// $ Fillarray can be a string, such as "test". echo"

";      
  print_r ($arrayFilled);       
 echo "

";

$ Keys = array ("string", "2", 9, "SDK", "PK"); $ array2 = array_fill_keys ($ keys, "testing"); echo"

";        print_r ($array2);        echo "

";?> Running result:

Array (

[0] => Array

(

[0] =>

[1] => B

[2] => c

[3] => d

)

[1] => Array

(

[0] =>

[1] => B

[2] => c

[3] => d

)

[2] => Array

(

[0] =>

[1] => B

[2] => c

[3] => d

)

[3] => Array

(

[0] =>

[1] => B

[2] => c

[3] => d

)

[4] => Array

(

[0] =>

[1] => B

[2] => c

[3] => d

)

)

Array

(

[String] => testing

[2] => testing

[9] => testing

[SDK] => testing