Page 355 - Computer science 868 Class 12
P. 355

Method                           Example                               Output
                           append()      StringBuffer s1 = new StringBuffer("comp") ; computer

                                         StringBuffer s2 = new StringBuffer("uter");
                                         System.out.println(s1.append(s2));
                           setCharAt()   StringBuffer s1 = new StringBuffer("Rimi");  Rima

                                         s1.setCharAt(3,'a');
                                         System.out.println(s1);
                           insert()      StringBuffer s1 = new StringBuffer("Rimi a  Rimi is a good student
                                         good student");

                                         StringBuffer s2 = new StringBuffer("is ");
                                         s1.insert(5,s2);
                                         System.out.println(s1);
                           delete()      StringBuffer s1 = new StringBuffer("indiiaan");  indian

                                         s1.delete(4,6);
                                         System.out.println(s1);
                           setLength()   StringBuffer  s1 = new StringBuffer("India  India is a country India
                                         is a country");                                      is a

                                         System.out.println(s1);                              Note:  This  shows  that
                                                                                              the extra characters are
                                         s1.setLength(10);
                                                                                              removed.
                                         System.out.println(s1);
                           reverse()     StringBuffer  s1 = new StringBuffer("India  India is a country
                                         is a country");
                                                                                              yrtnuoc a si aidnI
                                         System.out.println(s1);
                                                                                              Note:  The  sentence  is
                                         s1.reverse();                                        reversed character wise
                                         System.out.println(s1);

                     10.4 CONVERSION FROM STRING TO PRIMITIVE DATA TYPES AND VICE VERSA

                 10.4.1 Use of Wrapper class to do Conversions
                 1.  Converts String to primitive data types:
                   •   <Wrapper class>.valueOf(String str):  This method is used to convert the string str to its primitive data type using
                     the wrapper class.

                    Syntax: <primitive type> <variable> = <Wrapper class>.valueOf(String str);
                     For example,

                       String str1= "234";
                       int n=Integer.valueOf(str1);                // converts "234" to 234
                       String str1= "27.83";
                       double d=Double.valueOf(str1);              // converts "27.83" to 27.83
                   •  <Wrapperclass>.pasre<primitive datatype>(String): This method is also used to do the same conversions.
                     For example,

                       String str1= "234";
                       int n=Integer.pasreInt(str1);               // converts "234" to 234


                       String str1= "27.83";
                       double d=Double.parseDouble(str1);          // converts "27.83" to 27.83


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