When you look at a string instrument, the first thing you'll probably notice is that it's made of wood, so why is it called a string instrument? The bodies of the string instruments, which are hollow inside to allow sound to vibrate within them, are made of different kinds of wood, but the part of the instrument that makes the sound is the strings, which are made of nylon, steel or sometimes gut. The strings are played most often by drawing a bow across them. The handle of the bow is made of wood and the strings of the bow are actually horsehair from horses' tails! Sometimes the musicians will use their fingers to pluck the strings, and occasionally they will turn the bow upside down and play the strings with the wooden handle. The strings are the largest family of instruments in the orchestra and they come in four sizes: the violin, which is the smallest, viola, cello, and the biggest, the double bass, sometimes called the contrabass.
Examples and practices described in this don't take advantage of improvements introduced in later releases and might use technology no longer available.
Strings, which are widely used in Java programming, are a sequence of characters. In the Java programming language, strings are objects.
The Java platform provides the String class to create and manipulate strings. In this case, "Hello world!
As with any other object, you can create String objects by using the new keyword and a constructor. The String class has thirteen constructors that allow you to provide the initial value of the string using different sources, such as an array of characters:. Methods used to obtain information about an object are known as accessor methods.
One accessor method that you can use with strings is the length method, which returns the of characters contained in the string object. After the following two lines of code have been executed, len equals Here is a short and inefficient program to reverse a palindrome string. It invokes the String method charAt iwhich returns the i th character in the string, counting from 0.
The string family
To accomplish the string reversal, the program had to convert the string to an array of characters first for loopreverse the array into a second array second for loopand then convert back to a string. The String class includes a method, getCharsto convert a string, or a portion of a string, into an array of characters so we could replace the first for loop in the program above with. For example:.
Such a concatenation can be a mixture of any objects. For each object that is not a Stringits toString method is called to convert it to a String.
You have seen the use of the printf and format methods to print output with formatted s. The String class has an equivalent class method, formatthat returns a String object rather than a PrintStream object.
Using String's static format method allows you to create a formatted string that you can reuse, as opposed to a one-time print statement. For example, instead of. All rights reserved.
Hide TOC. s and Strings. Note: The String class is immutable, so that once it is created a String object cannot be changed.
The String class has a of methods, some of which will be discussed below, that appear to modify strings. Since strings are immutable, what these methods really do is create and return a new string that contains the result of the operation.