Leilin Peng Share: PHP array

  An array of a plurality of values ​​can be stored in a single variable:

  

  $cars=array("Volvo","BMW","Toyota");

  echo "I like " . $cars[0] . ", " . $cars[1] . " and " . $cars[2] . ".";

  ?>

  What arrays are?

  An array is a special variable can store multiple values ​​in a single variable.

  If you have a list of items (for example: car name list), which is stored in a single variable, as follows:

  $cars1="Volvo";

  $cars2="BMW";

  $cars3="Toyota";

  However, if you want to loop through the array and find a specific one? If the array of items more than three but 300 it?

  The solution is to create an array!

  Arrays can store multiple values ​​in a single variable, and you can access them according to the key value.

  Create an array in PHP

  In PHP, array () function is used to create an array:

  array();

  In PHP, there are three types of arrays:

  Numeric array - the array with numeric keys ID

  Associative array - with the specified array of keys, each key associated with a value

  Multidimensional array - containing one or more arrays of arrays

  PHP array of numbers

  There are two ways to create a numeric array:

  Automatically assigned an ID key (key ID is always starts from 0):

  $cars=array("Volvo","BMW","Toyota");

  Artificial assigned ID keys:

  $cars[0]="Volvo";

  $cars[1]="BMW";

  $cars[2]="Toyota";

  The following example creates an array called value of $ cars, and assigned to the three elements of the array, and then print the text section contains an array of values:

  

  $cars=array("Volvo","BMW","Toyota");

  echo "I like " . $cars[0] . ", " . $cars[1] . " and " . $cars[2] . ".";

  ?>

  Get the length of the array - count () function

  count () function returns the length of the array (number of elements):

  

  $cars=array("Volvo","BMW","Toyota");

  echo count($cars);

  ?>

  Traversing the array of numbers

  All numerical values ​​and traverse the print array, you can use a for loop, as follows:

  

  $cars=array("Volvo","BMW","Toyota");

  $arrlength=count($cars);

  for($x=0;$x<$arrlength;$x++)

  {

  echo $cars[$x];

  echo "
";

  }

  ?>

  PHP associative array

  Associative array is specified using an array of key you assigned to the array.

  There are two ways to create associative arrays:

  $age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");

  or:

  $age['Peter']="35";

  $age['Ben']="37";

  $age['Joe']="43";

  You can then use the specified key in the script:

  

  $age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");

  echo "Peter is " . $age['Peter'] . " years old.";

  ?>

  Traversing associative arrays

  Through and print all values ​​in an associative array, you can use a foreach loop, as follows:

  

  $age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");

  foreach($age as $x=>$x_value)

  {

  echo "Key=" . $x . ", Value=" . $x_value;

  echo "
";

  }

  ?>

  Multidimensional Arrays

  Multidimensional array will be described in detail in the advanced section of the tutorial PHP.

  Complete PHP Array Reference

  For a complete reference manual for all array functions, visit our PHP Array Reference Manual.

  The reference manual provides a brief description of each function and application examples!

  View all PHP tutorial article: https://www.codercto.com/courses/l/5.html (edit: Leilin Peng Source: network intrusion deleted)

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Origin www.cnblogs.com/linpeng1/p/10983447.html