public class CountChar { public static int upperCase = 0; public static int lowerCase = 0; public static int digital = 0; public static void main(String[] args) { String str = "skjHKL131lsdjf"; char[] c = str.toCharArray(); for (int i = 0; i < c.length; i++) { if (c[i] > 'a' && c[i] < 'z') upperCase++; else if (c[i] > 'A' && c[i] < 'Z') lowerCase++; else digital++; } System.out.println("大写字母的个数:" + upperCase); System.out.println("小写字母的个数:" + lowerCase); System.out.println("数字的个数:" + digital); }}
public class cutString { public static void main(String[] args) { String str = "accpHelloWorldFininaKK"; char[] c = str.toCharArray(); for (int i = 0; i < c.length; i++) { if (c[i] > 'A' && c[i] < 'Z') { System.out.print("," + c[i]); continue; } else System.out.print(c[i]); } } }
import java.util.regex.Matcher; import java.util.regex.Pattern;public class EmailTest { public static void main(String[] args) { String line = "[email protected]"; parse(line); } private static void parse(String line) { Pattern p = Pattern.compile("[\\w[.-]]+@[\\w[.-]]+\\.[\\w]+"); Matcher m = p.matcher(line); if (m.find()) System.out.println(m.group()); else System.out.println("不匹配!!!"); }}
终于都写完了,呵呵 ,楼主参考一下!!!建议楼主多动手,多思考!/** * 四舍五入: 任意数字进行四舍五入,要求保留小数位2位,并且从末尾开始四舍五入 比如: 3.149===>3.15 3.1445==>3.15 * 3.997===>4.00 */ public class RoundTest { public static void main(String[] args) { double number = 3.1444445; String str = String.valueOf(number); parse(str); } /** * 截取str小数点后面两位的所有数字,问保存到另一个 字符串ss中,对ss中的数字从最后位数开始进行判断 * 如果最后面的数大于等5,则倒数第二个数加1,以此类 推。最后判断小数点后的第三位是否大于等于5,如果是 则str保留到小数点后面两位的数 加 * 0.01 * * @param str * 进行四舍五入的字符串 */ public static void parse(String str) { int index = str.indexOf("."); String s = str.substring(0, index + 3); double digital = Double.parseDouble(s); String ss = str.substring(index + 3, str.length()); int b = 0; if (ss.length() == 1) { int c = Integer.parseInt(ss.charAt(0) + ""); if (c >= 5) digital += 0.01; } else if (ss.length() > 1) { int a = 0; for (int i = ss.length() - 1; i > 0; i--) { a = Integer.parseInt(ss.charAt(i) + ""); if (b >= 5) { a += 1; } b = Integer.parseInt(ss.charAt(i - 1) + ""); if (a >= 5) { b += 1; } } if (b >= 5) digital += 0.01; } System.out.println(str + "==>" + digital); } }
public class CountChar { public static int upperCase = 0;
public static int lowerCase = 0;
public static int digital = 0; public static void main(String[] args) {
String str = "skjHKL131lsdjf";
char[] c = str.toCharArray();
for (int i = 0; i < c.length; i++) { if (c[i] > 'a' && c[i] < 'z')
upperCase++;
else if (c[i] > 'A' && c[i] < 'Z')
lowerCase++;
else
digital++; } System.out.println("大写字母的个数:" + upperCase);
System.out.println("小写字母的个数:" + lowerCase);
System.out.println("数字的个数:" + digital); }}
public class cutString {
public static void main(String[] args) {
String str = "accpHelloWorldFininaKK";
char[] c = str.toCharArray(); for (int i = 0; i < c.length; i++) {
if (c[i] > 'A' && c[i] < 'Z') {
System.out.print("," + c[i]);
continue;
} else
System.out.print(c[i]);
}
}
}
import java.util.regex.Matcher;
import java.util.regex.Pattern;public class EmailTest { public static void main(String[] args) { String line = "[email protected]";
parse(line);
} private static void parse(String line) {
Pattern p = Pattern.compile("[\\w[.-]]+@[\\w[.-]]+\\.[\\w]+");
Matcher m = p.matcher(line);
if (m.find())
System.out.println(m.group());
else
System.out.println("不匹配!!!");
}}
* 四舍五入: 任意数字进行四舍五入,要求保留小数位2位,并且从末尾开始四舍五入 比如: 3.149===>3.15 3.1445==>3.15
* 3.997===>4.00
*/
public class RoundTest { public static void main(String[] args) {
double number = 3.1444445;
String str = String.valueOf(number);
parse(str);
} /**
* 截取str小数点后面两位的所有数字,问保存到另一个 字符串ss中,对ss中的数字从最后位数开始进行判断
* 如果最后面的数大于等5,则倒数第二个数加1,以此类 推。最后判断小数点后的第三位是否大于等于5,如果是 则str保留到小数点后面两位的数 加
* 0.01
*
* @param str
* 进行四舍五入的字符串
*/
public static void parse(String str) {
int index = str.indexOf(".");
String s = str.substring(0, index + 3);
double digital = Double.parseDouble(s);
String ss = str.substring(index + 3, str.length());
int b = 0; if (ss.length() == 1) {
int c = Integer.parseInt(ss.charAt(0) + "");
if (c >= 5)
digital += 0.01;
} else if (ss.length() > 1) {
int a = 0;
for (int i = ss.length() - 1; i > 0; i--) {
a = Integer.parseInt(ss.charAt(i) + "");
if (b >= 5) {
a += 1;
}
b = Integer.parseInt(ss.charAt(i - 1) + "");
if (a >= 5) {
b += 1;
}
}
if (b >= 5)
digital += 0.01; } System.out.println(str + "==>" + digital);
}
}
public class CutStringTest
{
public static void main(String[] args)
{
String str = "accpHelloWorldFininaKK";
for (int i = 0; i<str.length(); i++)
{
if(Character.isUpperCase(str.charAt(i)))
{
str = str.substring(0,i)+","+str.substring(i,str.length());
i++;
}
}
String[] strArray = str.split(",");
for(int i = 0;i<strArray.length;i++)
{
System.out.println(strArray[i]);
}
}
}
用StringBuffer做:
public class CutStringTest
{
public static void main(String[] args)
{
StringBuffer str = new StringBuffer("accpHelloWorldFininaKK");
for(int i = 0;i<str.length();i++)
{
if (Character.isUpperCase(str.charAt(i)))
{
str.insert(i,",");
i++;
}
}
String newStr = str.toString();
String[] strArray = newStr.split(",");
for (int i = 0; i<strArray.length; i++)
{
System.out.println(strArray[i]);
}
}
}
计算机专业的?