#PHP ASSOCIATIVE ARRAY KEY TOGGLE HOW TO#
#PHP ASSOCIATIVE ARRAY KEY TOGGLE CODE#

This is true: key Dried Mulberries has value 3.00 $books = array('The Eater's Guide to Chinese Characters', 'Cashew Nuts and White Mushrooms' => 4.95, Than how their keys would usually be ordered, this could produce unexpected results. If you have a numeric array whose elements were added in a different order The first element added is accessed first, the second element added is accessed next,Īnd so on. ), the elements are accessed in the order that they were added to the array. When you iterate through an array using foreach( No need to use a separate variable, such as $color_index in Example 4-8, to This value alternates between 0Īnd 1 as $i alternates between even and odd. This is shown inįor ($i = 0, $num_dishes = count($dinner) $i ' Įxample 4-12 computes the correct table rowĬolor with $i % 2. Your for( ) loop shouldĭepend on a loop variable that starts at 0 andĬontinues up to one less than the number of elements in the array. So, if you want to know what element youâre on as youâre iterating through a numericĪrray, use for( ) instead of foreach( ). Thereâs no loop structure that gives you both at once. The foreach( ) loop gives you the value ofĮach array element, but the for( ) loop gives you the With for( ), you get the position explicitly in your loop

#PHP ASSOCIATIVE ARRAY KEY TOGGLE CODE#

), you have to use a separate variable that you increment each time theįoreach( ) code block runs.

To keep track of your position in the array with foreach( Variable name after as, and each element value isĬopied into that variable inside the code block. With this form of foreach( ), just specify one $dinner = array('Sweet Corn and Asparagus',Įxample 4-10 prints: You can eat: Sweet Corn and Asparagus Use the $key variable as an index into the array.Įxample 4-9 uses this technique to double Loop variables like $key and $value doesnât affect the actual array. Inside the foreach( ) code block, changing the This switches $color_index between 0 and 1 ExampleĤ-8 alternates between the two color values in its $row_color array. Then, switch a variable between 0 and 1 each time through the foreach( This is easy to do when you store the alternating color values in a separate array. When youâre using foreach( ) to print out data inĪn HTML table, often you want to apply alternating colors or styles to each table row. If the variable names were in use before the foreach( ), though, theyâre overwritten with values from You can use whatever variable names you want for the keyĪnd value inside the code block. In Example 4-7, that code prints $key and $value with Then, it runs the code inside the curly braces. 'dinner' => 'Eggplant with Chili Sauce') įor each element in $meal, foreach( ) copies the key of the element into $key and the value into $value. 'lunch' => 'Cashew Nuts and White Mushrooms', $meal = array('breakfast' => 'Walnut Bun', When you retrieve informationįrom a database as described in Chapter 7, that data The PHP interpreter automatically puts into an array for you.

#PHP ASSOCIATIVE ARRAY KEY TOGGLE HOW TO#

Last, Section 4.5 explores arrays that themselvesĬhapter 6 shows you how to process form data, which Introduces the implode( ) and explode( ) functions, which turn arrays into strings and strings into arrays.Īnother kind of array modification is sorting, which is discussed in Section 4.4. Section 4.2 explains how to do these things with Frequently, youâll want to do something with each element in anĪrray, such as print it or inspect it for certain conditions. Section 4.1, next, goes over fundamentals such as how to create arrays and This chapter shows you how to work with arrays. An array is a container that holds multiple In Chapter 2, you learned that a variable So this works best when casting StdClass objects or objects with only public properties.Arrays are collections of related values, such as theĭata submitted from a form, the names of students in a class, or the populations of a list Typecasting this way will not do deep casting of the object graph and you need to apply the null bytes to access any non-public attributes. Output with var_export instead of var_dump : array ( ''.

These prepended values have null bytes on either side.Įxample: Simple Object $object = new StdClass $object->foo = 1 $object->bar = 2 var_dump( (array) $object )

The keys are the member variable names, with a few notable exceptions such as the integer properties are inaccessible and protected variables have a '*' prepended to the variable name. If an object is converted to an array, the result is an array whose elements are the object's properties.

Php associative array key toggle