String in C

5 Key excerpts on "String in C"

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  eBook - ePub

  Learn C Programming

  A beginner's guide to learning C programming the easy and disciplined way

  • Jeff Szuhay(Author)
  • 2020(Publication Date)
  • Packt Publishing

    (Publisher)

  Working with Strings

  In C, a string is an array with two special properties. First, a string is made up of only characters. Second, the string must conclude with an essential terminating character—the null character. While some would say strings are one of C's weakest features, I disagree with that assessment. Because strings build on already-established mechanisms, I believe that they are rather elegant in an unexpected way.

  Not all values that we might want to manipulate in a program are numbers. Often, we need to manipulate words, phrases, and sentences; these are built from strings of characters. We have been performing output using simple strings in printf() statements. In order to perform the input of strings and numbers, we need to be able to further manipulate strings to convert them into values. In this chapter, the elements and building blocks of C strings will be explored, as well as various ways to use and manipulate C strings.

  Chapter 11 , Working with Arrays , Chapter 13 , Using Pointers , and Chapter 14 , Understanding Arrays and Pointers , are essential to understanding the concepts presented here. Please do not skip those chapters, particularly Chapter 14 , Understanding Arrays and Pointers , before reading this one.

  The following topics will be covered in this chapter:

  • Characters – the building blocks of strings
  • Exploring C strings
  • Understanding the strengths and weaknesses of C strings
  • Declaring and initializing a string
  • Creating and using an array of strings
  • Using the standard library for common operations on strings
  • Preventing some pitfalls of strings – safer string operations

  Throughout this chapter, we will introduce the programming technique of iterative program development

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  eBook - PDF

  Embedded Microcontroller Interfacing for M-COR ® Systems

  • G. Jack Lipovski, J. David Irwin(Authors)
  • 2000(Publication Date)
  • Academic Press

    (Publisher)

  A string is a sequence of elements such that after the /th element has been accessed, only the (/ + l)st element, the (/ — l)th, or both, can be accessed. In particular, a string of characters, stored using the ASCII code shown in Table 2.4, is an ASCII character string and is used to store text. The ASCII code of a character is stored as a 7-bit code in a c h a r variable. Character constants are enclosed by single quotes around the character, as 'A' is the character A. Special characters are null '0 line feed 'n tab 't', form feed ' f (begin on new page), cr carriage return 'r', and ' ' space. Strings are allocated and used in C as if they were char vectors, initiahzed by putting the characters in double quotes, and end in the null character '0 (Allow an extra byte for it.) One can initialize a character c to be the code for the letter a and a string s to be ABCD with the declaration: char c='a s [5] =''ABCD'' ; Strings are also very useful for input and output when debugging C programs; we will discuss the use of strings when we describe the/7r/«(/'function later. However, a source-level debugger for a C compiler provides better debugging tools. Even so, some discussion of string-oriented input and output is generally desirable for human interfacing. This discussion of loStreams will be done in §4.4.5 and §5.3.5. Table 2.4. ASCII Codes 0 1 2 3 4 5 6 7 8 9' A B C D E F 00 10 w ^n' r V 20 i* 1 (( # $ % & * ( ) it -¥ f -, / % 0 1 2 3 4 5 6 7 8 9 « ) < s > ? 40 @ A B C D E F G H 1 J K L M N 0 50 P Q R S T U V W X Y Z { ] A -60 1 a b c d e f 9 h r i k 1 m n 0 70 P q r $ t u V w X • -y 2 { 1 } rsj 2.2 Data Structures 53 Characters in strings can be accessed by indexing or by pointers. An index can be incremented to access each character, one after another from first to last character.

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  eBook - ePub

  Learn C Programming

  • Jeff Szuhay(Author)
  • 2022(Publication Date)
  • Packt Publishing

    (Publisher)

  Chapter 15 : Working with Strings

  In C, a string is an array with two special properties. First, a string is made up of only characters. Second, the string must conclude with an essential terminating character – the NUL  character. While some would say strings are one of C's weakest features, I disagree with that assessment. Because strings build on already-established mechanisms, I believe that they are rather elegant in an unexpected way.

  Not all values that we might want to manipulate in a program are numbers. Often, we need to manipulate words, phrases, and sentences; these are built from strings of characters. We have been getting output using simple strings in printf()  statements. To input strings and numbers, we need to be able to manipulate strings even further so that we can convert them into values. In this chapter, we will explore the elements and building blocks of C strings, as well as various ways to use and manipulate C strings.

  Chapter 11 , Working with Arrays , Chapter 13 , Using Pointers , and Chapter 14 , Understanding Arrays and Pointers , are essential to understanding the concepts presented here. Please do not skip those chapters, particularly Chapter 14 , Understanding Arrays and Pointers , before reading this one.

  The following topics will be covered in this chapter:

  • Characters – the building blocks of strings
  • Exploring C strings
  • Understanding the strengths and weaknesses of C strings
  • Declaring and initializing a string
  • Creating and using an array of strings
  • Using the standard library for performing common operations on strings
  • Preventing some pitfalls of strings – safer string operations

  Throughout this chapter, we will introduce a programming technique called iterative program development

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  C++ for Mathematicians

  An Introduction for Students and Professionals

  • Edward Scheinerman(Author)
  • 2006(Publication Date)
  • CRC Press

    (Publisher)

  An ordered list of characters is generally called a character string . For example, the words Hello Gauss are such a list comprising 11 characters. As mentioned, C++ has two principal ways to work with character strings: as null-terminated char arrays and as objects of the class string . The character array representation is a primitive scheme inherited from the language C. It is useful for writing messages to the screen and other simple chores. The moment one wishes to do any manipulation of characters (e.g., concatenate two strings), the C++ string class makes program-289 290 C++ for Mathematicians ming much easier. We begin by discussing the basics of character arrays and then introduce the string class in the next section. In a statement such as cout<

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  Programming with C++

  • Kyla McMullen, Elizabeth Matthews, June Jamrich Parsons, , Kyla McMullen, Kyla McMullen, Elizabeth Matthews, June Jamrich Parsons(Authors)
  • 2021(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Module 5 CharaCter and String data typeS 69 Figure 5-9 Character functions Character Function/Method Example Data Result Check if the character is a letter of the alphabet isalpha(initial) isalpha(choice) Check if the character is a digit Change to uppercase Change to lowercase Display the character for the specified ASCII value Display the ASCII value for the character isdigit(initial) isdigit(choice) toupper(initial) tolower(initial) char(num) int(initial) initial = 'a' char choice = '2' char initial = 'a' char choice = '2' char initial = 'a' char initial = 'A' int num = 97 char initial = 'a' True False False True A a a 97 5.2 STRING DATA TYPES Working with String Data (5.2.1, 5.2.2, 5.2.3) A sequence of alphanumeric characters is classified as a string. You can use the string data type for working with variables that contain words, phrases, sentences, and other text. In some programming languages, strings are a primitive data type, but in other languages, they are a com- posite data type. In either case, your programming language provides a variety of tools for working with strings. String literals are typically enclosed in quotation marks for initialization statements, assignment statements, and prompts. The Alphabet Soup pseudocode in Figure 5-10 uses strings in several ways. initialize string your_name = " " Initializes your_name as an empty string. initialize string message = " likes alphabet soup." Initializes a variable containing a string. Quotes are required in the program statement. display "What is your name? " Displays a prompt containing a string. input your_name Collects a user-input string such as Skylar Jones.

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