![]() ![]() While loop is used to execute a block of code as long as the set condition is made to be false. Here’s the thing: if, and only if, the key is a numeric literal, then it is automatically converted into an integer at the start of the loop. The for statement is used when you know how many times you want to execute a statement or a block of statements. The foreach loop is used to loop through arrays. Inside foreach loops you can access every key/value pair of the array you are iterating, and sometimes you may need to compare the key with some other value. We will discuss about continue and break keywords used to control the loops execution. While − loops through a block of code if and as long as a specified condition is true.ĭo.while − loops through a block of code once, and then repeats the loop as long as a special condition is true.įoreach − loops through a block of code for each element in an array. Combining foreach and while in PHP Ask Question Asked 9 years, 9 months ago Modified 4 years, 9 months ago Viewed 32k times 10 This seems like it should be a simple question, but I can't find a good answer. PHP supports following four loop types.įor − loops through a block of code a specified number of times. The key difference between the two is that foreach automatically starts at the front of the array, whereas list()/ each() does not.Loops in PHP are used to execute the same block of code a specified number of times. In practice, however, you will find foreach loops and list()/ each() loops in about equal proportions, despite the latter option being slower. Generally speaking, using foreach loops is the most optimised way to loop through an array, and is also the easiest to read. There is a lot more detail on array cursors later. The meaning of that first line is "get the current element in the array, and assign its key to $var and its value to $val, then advance the array cursor. To start with, each() will return the first element, then the second element, then the third, and so on, until it finds there are no elements left, in which case it will return false and end the loop. ![]() All arrays have a cursor, and you can freely move it around - it is used in the while loop above, where we need to iterate through an array. "Array cursor" is the technical term for the element of an array that is currently being read. This is used frequently in many scripts where a common block of code to be executed. Each() takes an array as its parameter, and returns the current key and value in that array before advancing the array cursor. For loop in PHP is used to iterate through a section in an application. List() is a function that does the opposite of array() - it takes an array, and converts it into individual variables. The second way to use foreach does allow you to extract keys, and looks like this:Īnother commonly used way to loop over arrays is using the list() and each() functions, like this: In this situation, the array keys are ignored completely, which usually makes most sense when they have been auto-generated (i.e. Here the array $array is looped through and its values are extracted into $val. The easiest way to use foreach looks like this: However, there is a quick and easy way to accomplish the same thing: a foreach loop, which itself has two versions. As a result, code like this should generally be avoided: That is, it can have its keys out of order or entirely missing. For example, an array may have keys 0, 1, 2, 5, 3, 6, 7. However, these numbers cannot be guaranteed to exist within the array in any given order, or even to exist at all - they are just key values themselves. If you do not specify a key, as in the first example, PHP will just assign incrementing numbers starting with 0. ![]()
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