//StringMisc.java
// This program demonstrates the length, charAt and getChars
// methods of the String class.
//
// Note: Method getChars requires a starting point
// and ending point in the String. The starting point is the
// actual subscript from which copying starts. The ending point
// is one past the subscript at which the copying ends.
import javax.swing.*;
public class StringMisc {
public static void main( String args[] )
{
String s1, output;
char charArray[];
s1 = new String( "hello there" );
charArray = new char[ 5 ];
// output the string
output = "s1: " + s1;
// test the length method
output += "\nLength of s1: " + s1.length();
// loop through the characters in s1 and display reversed
output += "\nThe string reversed is: ";
for ( int i = s1.length() - 1; i >= 0; i-- )
output += s1.charAt( i ) + " ";
// copy characters from string into char array
//四个参数的含义
//1.被拷贝字符在字串中的起始位置
//2.被拷贝的最后一个字符在字串中的下标再加1
//3.目标字符数组
//4.拷贝的字符放在字符数组中的起始下标
s1.getChars( 0, 5, charArray, 0 );
output += "\nThe character array is: ";
for ( int i = 0; i < charArray.length;i++ )
output += charArray[ i ];
JOptionPane.showMessageDialog( null, output,
"Demonstrating String Class Constructors",
JOptionPane.INFORMATION_MESSAGE );
System.exit( 0 );
}
}
}
- Length():获取字串长度 《空格也算他的长度》
- charAt():获取指定位置的字符
- getChars():获取从指定位置起的子串复制到字符数组中(它有四个参数,在示例中有介绍)
- replace():子串替换
- toUpperCase()、 toLowerCase():大小写转换
- trim():去除头尾空格:
- toCharArray():将字符串对象转换为字符数组