Len (programming)

Many common programming languages operate on strings using string functions. One of the major string functions Len, returns the length of a specific string.

This function is called Len, which stands for length, in the language BASIC and its derivatives such as Visual Basic. It is called strlen in the language C and its derivatives such as PHP. In some other languages, the entire word "length" is written out as the name of the function. For other languages see string functions.

Use in other languages

To see a list of uses in other languages see the length section in

Main article: String Functions (Computer Science)

Use in Visual Basic

In Visual Basic, the prototype of the Len function is this:

 Function Len (ByVal Str As String)

An example below shows an example of the use of Len function.

Sub Main()
    Dim Str As String
    Dim Int As Integer
    Str = InputBox("Enter a string")
    Int = Len(Str)
    MsgBox(CStr(Int))
End Sub

This function reads a string from an input box and outputs its length.

For example, the input "Hello!" will output 6.

Use in Python

In Python, len() can be used to denote the length of a string:

>>> something = 'Wikipedia'
>>> len(something)
9

where the word "Wikipedia" clearly has 9 letters. Consider also the example of "I am John"

>>> len('I am John')
9

because "I am John" clearly has 9 characters (keep in mind that spaces are counted as well).

The function len() can also be used to find the size (i.e. number of elements) of lists, tuples, dictionaries, sets, and other sequence types (any object that implements a __len__() method can be used). Here the list p includes 3 entries:

>>> p = ['Wikipedia', 'Wiktionary', 'Wikibooks']
>>> len(p)
3

Use in Go

In Go, len() can be used to obtain the length of a string, array, or slice, the number of keys in a map, or the number of elements queued in a channel.