Learn to Program with C_ Learn to Program using the Popular C Programming Language ( PDFDrive )

Recommendations

Info

Chapter 6CharactersIn this chapter, we will explain the following:• Some important features of character sets• How to work with character constants and values• How to declare character variables in C• How you can use characters in arithmetic expressions• How to read, manipulate, and print characters• How to test for end-of-line using \n• How to test for end-of-file using EOF• How to compare characters• How to read characters from a file• How to convert a number from character to integer6.1 Character SetsMost of us are familiar with a computer or typewriter keyboard (called the standard Englishkeyboard). On it, we can type the letters of the alphabet (both uppercase and lowercase), thedigits and other ‘special’ characters like +, =, <, >, &, and %—these are the so-called printablecharacters.On a computer, each character is assigned a unique integer value, called its code. This codemay be different from one computer to another depending on the character set being used. Forexample, the code for A might be 33 on one computer but 65 on another.Inside the computer, this integer code is stored as a sequence of bits; for example, the 6-bitcode for 33 is 100001 and the 7-bit code for 65 is 1000001.Nowadays, most computers use the ASCII (American Standard Code for InformationInterchange) character set for representing characters. This is a 7-bit character standard thatincludes the letters, digits, and special characters found on a standard keyboard. It also includescontrol characters such as backspace, tab, line feed, form feed, and carriage return.141www.it-ebooks.info
Chapter 6 ■ CharactersThe ASCII codes run from 0 to 127 (the range of numbers that can be stored using 7 bits).The ASCII character set is shown in Appendix B. Interesting features to note are the following:• The digits 0 to 9 occupy codes 48 to 57.• The uppercase letters A to Z occupy codes 65 to 90.• The lowercase letters a to z occupy codes 97 to 122.Note, however, that even though the ASCII set is defined using a 7-bit code, it is stored onmost computers in 8-bit bytes—a 0 is added at the front of the 7-bit code. For example, the 7-bitASCII code for A is 1000001; on a computer, it is stored as 01000001, occupying one byte.In this book, as far as is possible, we will write our programs making no assumptions aboutthe underlying character set. Where it is unavoidable, we will assume that the ASCII character setis used. For instance, we may need to assume that the uppercase letters are assigned consecutivecodes, similarly for lowercase letters. This may not necessarily be true for another character set.Even so, we will not rely on the specific values of the codes, only that they are consecutive.6.2 Character Constants and ValuesA character constant is a single character enclosed in single quotes such as ‘A’, ‘+’ and ‘5’. Somecharacters cannot be represented like this because we cannot type them. Others play a specialrole in C (e.g. ', \). For these, we use an escape sequence enclosed in single quotes. Some examplesare shown in the following table:char description Code'\n' new line 10'\f' form feed 12'\t' tab 9'\'' single quote 39'\\' backslash 92The character constant '\0' is special in C; it is the character whose code is 0, normallyreferred to as the null character. One of its special uses is to indicate the end of a string in memory(see Chapter 8).The character value of a character constant is the character represented, without the singlequotes. Thus, the character value of 'T' is T and the character value of '\\' is \.A character constant has an integer value associated with it—the numeric code of the characterrepresented. Thus, the integer value of 'T' is 84 since the ASCII code for T is 84. The integer value of'\\' is 92 since the ASCII code for \ is 92. And the integer value of '\n' is 10 since the ASCII codefor the newline character is 10.142www.it-ebooks.info
Page 1 and 2:
THE EXPERT’S VOICE® IN PROGRAMMI
Page 3 and 4:
Learn to Program with CCopyright ©
Page 5 and 6:
Contents at a GlanceAbout the Autho
Page 7 and 8:
■ Contents1.7 Write Output with p
Page 9 and 10:
■ Contents■Chapter ■ 5: Progr
Page 11 and 12:
■ Contentsxii7.11 Some Character
Page 13 and 14:
About the AuthorDr. Noel Kalicharan
Page 15 and 16:
AcknowledgementsI would like to exp
Page 17 and 18:
■ PrefaceOf course, you must lear
Page 19 and 20:
Chapter 1 ■ Elementary Programmin
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Chapter 2C - The BasicsIn this chap
Page 41 and 42:
Chapter 2 ■ C - The Basicstokenin
Page 43 and 44:
2.3.2 Reserved WordsChapter 2 ■ C
Page 45 and 46:
2.5 Integer Numbers - intChapter 2
Page 47 and 48:
Chapter 2 ■ C - The Basicsis eval
Page 49 and 50:
Chapter 2 ■ C - The BasicsEach nu
Page 51 and 52:
Chapter 2 ■ C - The Basics6 says
Page 53 and 54:
Chapter 2 ■ C - The BasicsIf op1
Page 55 and 56:
Chapter 2 ■ C - The BasicsThe val
Page 57 and 58:
2.8 The Assignment StatementChapter
Page 59 and 60:
Chapter 2 ■ C - The BasicsExercis
Page 61 and 62:
Chapter 2 ■ C - The Basics30. Wha
Page 63 and 64:
Chapter 3 ■ Programs with Sequenc
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Chapter 4Programs with Selection Lo
Page 81 and 82:
Chapter 4 ■ Programs with Selecti
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104: Chapter 4 ■ Programs with Selecti
Page 105 and 106: Chapter 5 ■ Programs with Repetit
Page 153: Chapter 5 ■ Programs with Repetit
Page 157 and 158: Chapter 6 ■ CharactersIn this cas
Page 159 and 160: Chapter 6 ■ CharactersHThis would
Page 161 and 162: Chapter 6 ■ CharactersProgram P6.
Page 163 and 164: Chapter 6 ■ Characters6. The whil
Page 165 and 166: Chapter 6 ■ Characters6.6 Count C
Page 167 and 168: Chapter 6 ■ Charactersnumber of c
Page 169 and 170: Chapter 6 ■ Characters6.9 Read Ch
Page 171 and 172: Chapter 6 ■ CharactersThis proble
Page 173 and 174: Chapter 6 ■ CharactersTo get arou
Page 175 and 176: Chapter 6 ■ CharactersThe sequenc
Page 177 and 178: Chapter 6 ■ Characters11. Write a
Page 179 and 180: Chapter 7 ■ Functions7.2 skipLine
Page 181 and 182: Chapter 7 ■ FunctionsWhen we wish
Page 183 and 184: Chapter 7 ■ FunctionsIf, when a f
Page 185 and 186: Chapter 7 ■ FunctionsIn order to
Page 187 and 188: Chapter 7 ■ Functionsessentially
Page 189 and 190: Chapter 7 ■ FunctionsThe logic fo
Page 191 and 192: Chapter 7 ■ FunctionsSince lcm us
Page 193 and 194: Chapter 7 ■ Functions• The logi
Page 195 and 196: Chapter 7 ■ FunctionsWhen main is
Page 197 and 198: Chapter 7 ■ Functionsint factoria
Page 199 and 200: Chapter 7 ■ Functions7.10 Sum of
Page 201 and 202: Chapter 7 ■ Functions7.11 Some Ch
Page 203 and 204: Chapter 7 ■ Functionsint isLowerC
Page 205 and 206:
Chapter 7 ■ FunctionsThis fetches
Page 207 and 208:
Chapter 7 ■ Functions8. Write a f
Page 209 and 210:
Chapter 8ArraysIn this chapter, we
Page 211 and 212:
Chapter 8 ■ ArraysIn our example,
Page 213 and 214:
Chapter 8 ■ ArraysIf we wish to p
Page 215 and 216:
8.3.1 About Not Using Element 0Chap
Page 217 and 218:
Chapter 8 ■ ArraysPoints to note
Page 219 and 220:
Chapter 8 ■ ArraysThe complete pr
Page 221 and 222:
Chapter 8 ■ ArraysThis prints a l
Page 223 and 224:
Chapter 8 ■ ArraysYou can change
Page 225 and 226:
Chapter 8 ■ ArraysTo use the func
Page 227 and 228:
Chapter 8 ■ ArraysThe length of a
Page 229 and 230:
Chapter 8 ■ ArraysIn printf, the
Page 231 and 232:
Chapter 8 ■ ArraysSwapping two ch
Page 233 and 234:
Chapter 8 ■ ArraysIf all the lett
Page 235 and 236:
Chapter 8 ■ Arraysshe does this,
Page 237 and 238:
Chapter 8 ■ Arrays} //end letters
Page 239 and 240:
Chapter 8 ■ ArraysFigure 8-3. The
Page 241 and 242:
Chapter 8 ■ ArraysSuppose we have
Page 243 and 244:
Chapter 8 ■ ArraysSuppose a count
Page 245 and 246:
Chapter 8 ■ Arraysdelim = ch;whil
Page 247 and 248:
Chapter 8 ■ ArraysHere is the fun
Page 249 and 250:
Chapter 8 ■ ArraysBut what kind o
Page 251 and 252:
Chapter 8 ■ ArraysThis is a cleve
Page 253 and 254:
Chapter 8 ■ Arraysfprintf(out, "\
Page 255 and 256:
Chapter 9Searching, Sorting, and Me
Page 257 and 258:
Chapter 9 ■ Searching, Sorting, a
Page 259 and 260:
Page 261 and 262:
Page 263 and 264:
Page 265 and 266:
Page 267 and 268:
Page 269 and 270:
Page 271 and 272:
9.3.2 Insert an Element in PlaceCha
Page 273 and 274:
Page 275 and 276:
Page 277 and 278:
Page 279 and 280:
Page 281 and 282:
Page 283 and 284:
Page 285 and 286:
Page 287 and 288:
Page 289 and 290:
Page 291 and 292:
Chapter 10 ■ StructuresThe proble
Page 293 and 294:
Chapter 10 ■ StructuresFor this e
Page 295 and 296:
Chapter 10 ■ StructuresSince ther
Page 297 and 298:
Chapter 10 ■ Structures286Suppose
Page 299 and 300:
Chapter 10 ■ StructuresWe could e
Page 301 and 302:
Chapter 10 ■ Structuresint n = 0;
Page 303 and 304:
Chapter 10 ■ Structures10.7 Neste
Page 305 and 306:
Chapter 10 ■ Structuresint main()
Page 307 and 308:
Chapter 10 ■ Structures296A file,
Page 309 and 310:
Chapter 10 ■ Structureselseprint
Page 311 and 312:
Chapter 10 ■ StructuresTo find th
Page 313 and 314:
Chapter 10 ■ StructuresVoteCount
Page 315 and 316:
Chapter 10 ■ Structureswhile (k >
Page 317 and 318:
Chapter 10 ■ Structures6. A file
Page 319 and 320:
■ index• CCharactersarithmetic
Page 321 and 322:
■ index• N, ONamed constants.
Page 323:
■ indexStrings (cont.)for stateme
show all

Learn to Program with C_ Learn to Program using the Popular C Programming Language ( PDFDrive )

Create successful ePaper yourself

Delete template?

Save as template?