Java Programs Using Strings

Java+You, Download Today! Free Java Download » What is Java? And welcome to Up and Running with Java. Did you know that in July. Along the way you will be challenged with writing programs that include all the features that we'll be discussing.

Building Java Programs, 3rd edition Lab 3: Strings. Building Java Programs, 3rd edition Lab. Try solving this problem in Practice-It! C Programming Examples on Strings. The program in the following section checks if the two given strings are anagrams. The remaining programs in the section deal with listing. Java sample example codes, Java sample programs, Java Example Programs. JAVA EXAMPLE PROGRAMS: Publish Your Article Here Home; Fundamentals; Constructors. Although Java programs are cross-platform or platform independent.

String is Special - Java Programming Tutorial. A Brief Summary of the String Class. A Java String contains an immutable sequence of Unicode characters. Unlike C/C++, where string is simply an array of char, A Java String is an object of the class java. Java String is, however, special. Unlike an ordinary class: String is associated with string literal in the form of double- quoted texts such as . You can assign a string literal directly into a String variable, instead of calling the constructor to create a String instance.

The '+' operator is overloaded to concatenate two String operands. That is, its content cannot be modified once it is created. For example, the method to. Upper. Case() constructs and returns a new String instead of modifying the its existing content. The commonly- used method in the String class are summarized below.

Refer to the JDK API for java. String a complete listing. The format() method has the same form as printf(). For example. String. If you simply need to send a simple formatted string to the console, use System.

System. out. printf(. Hence, efficiency (in terms of computation and storage) is crucial. The designers of Java decided to retain primitive types in an object- oriented language, instead of making everything an object, so as to improve the performance of the language. On the other hand, objects are stored in the program heap, which require complex memory management and more storage spaces. For performance reason, Java's String is designed to be in between a primitive and a class.

The special features in String include: The '+' operator, which performs addition on primitives (such as int and double), is overloaded to operate on String objects. Take note that '+' does not work on any two arbitrary objects, such as Points or Circles. A String can be constructed by either.

String reference - just like a primitive, orvia the . String objects allocated via new operator are stored in the heap, and there is no sharing of storage for the same contents. String Literal vs. String Object. As mentioned, there are two ways to construct a string: implicit construction by assigning a string literal or explicitly creating a String object via the new operator and constructor. For example. String s. Modifying the content of one String directly may cause adverse side- effects to other Strings sharing the same storage.

JDK provides two classes to support mutable strings: String. Buffer and String. Builder (in core package java. A String. Buffer or String. Builder object is just like any ordinary object, which are stored in the heap and not shared, and therefore, can be modified without causing adverse side- effect to other objects. String. Builder class was introduced in JDK 1. It is the same as String.

Buffer class, except that String. Builder is not synchronized for multi- thread operations. However, for single- thread program, String. Builder, without the synchronization overhead, is more efficient.

String. Buffer. Read the JDK API specification for java. String. Buffer. You need to use a constructor to create a String. Buffer (instead of assigning to a String literal). Furthermore, '+' operator does not apply to objects, including the String. Buffer. You need to use a proper method such as append() or insert() to manipulating a String.

Buffer. To create a string from parts, It is more efficient to use String. Buffer (multi- thread) or String. Builder (single- thread) instead of via String concatenation. For example. int year = 2. String date. Str = new String.

Builder(). . append(year). The reverse() method is the fastest, which take about the same time for String. Builder and String.

Buffer. java. util. String. Tokenizer. Very often, you need to break a line of texts into tokens delimited by white spaces. The java. util. String. Tokenizer class supports this.

For example, the following program reverses the words in a String. It is recommended that anyone seeking this functionality use the split() method of String or the java.