java字符串替换问题

[海虎哥AI编程]

一字符串“1000000”
如何第4位为“0” 替换为“1” 如何写？
谢谢！！！！！

[seaforce]

不知道这种符不符合你的要求:
呵呵

/**
 * project_name: Test
 * package_name: netsource
 * package_declaration: package netsource;
 * filename: test11.java
 * author: yuhaiming
 * date: 2007-11-9
 */
package netsource;
import java.math.*;
public class test11 {
	public static void main(String[] args){
		String str = "1000000";

		String str1 = str.substring(0,3);
		String str2 = str.substring(4);
		String newString = str1+"1"+str2;
		System.out.println(newString);
	}
}

[anqier727]

public class Test
{
public static void main(String [] args)
{
String str = "1000000";
StringBuffer sb = new StringBuffer(str);
sb.setCharAt(3,'1');
System.out.println(sb);
}
}

[ps1981sophia]

class Test
{
	public static void main(String[] args) 
	{
		String str = "100000";
		if(str.charAt(3)=='0'){
		StringBuffer sb = new StringBuffer(str);
		sb.setCharAt(3,'1');
		str = sb.toString();
		}
		System.out.println("str:"+str);
	}
}

[hitzfc]

public class A{
public static void main(String[] args)
{
String h="1000001";
if(h.charSet(3)=='0')
h=h.subString(0,3)+"1"+h.subString(4,h.length());
}
}

[海虎哥AI编程]

楼上的方法好呵呵，谢谢了！！！ 下面是我自己写的
public class dfdfd {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
String str ="1001";
char c =str.charAt(3);
if(c=='1'){
String n= str.substring(0,3)+"0";
System.out.println("dfdfd"+n);
}

}

}