public static boolean filter(String content,String regex){ boolean result = Pattern.matches(regex,content); return result; } }问题一
问题二package com.ricky.www;public class TestString { public static void main(String[] args){ String[] strs = {"a1234","b1234","ba123456","cdlfd","dfdll"}; for(String str:strs){ if(filter(str,"b",0)){ System.out.println(str); } } } public static boolean filter(String content,String b,int index){ int temp = content.indexOf(b); boolean result = false; if(temp == index){ result = true; } return result; } }
package com.ricky.www;public class CountCharacter { public static void main(String[] args){ String content = "adafdadafdfdfadf"; String letterToFind = "a"; int result = countCharacter(content,letterToFind); System.out.println(letterToFind + " 出现 " + result + " 次在 " + content + " 中."); }
public static int countCharacter(String content,String ch){ String leave = content.replaceAll(ch,""); int result = content.length() - leave.length(); return result; } } 问题三
LZ真强, 把作业放到csdn让大家帮着做!
不是什么作业。自学java中。以前上学的时候压根就没看过~~~后悔了呵。还好有CSDN。
我运行了下三楼的代码出现这个错误: Exception in thread "main" java.lang.NoClassDefFoundError: FilterString (wrong n ame: com/ricky/www/FilterString) at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$100(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClassInternal(Unknown Source) 什么原因?
4.indexOf(String str)
5.indexOf(String str),substring(int beginIndex)
package com.ricky.www;import java.util.regex.Pattern;public class FilterString {
public static void main(String[] args){
String[] strs = {"a1234","b1234","ba123456","cdlfd","dfdll"};
String regex = "^b.*";
for(String str:strs){
if(filter(str,regex)){
System.out.println(str);
}
}
}
public static boolean filter(String content,String regex){
boolean result = Pattern.matches(regex,content);
return result;
}
}问题一
public static void main(String[] args){
String[] strs = {"a1234","b1234","ba123456","cdlfd","dfdll"};
for(String str:strs){
if(filter(str,"b",0)){
System.out.println(str);
}
}
}
public static boolean filter(String content,String b,int index){
int temp = content.indexOf(b);
boolean result = false;
if(temp == index){
result = true;
}
return result;
}
}
package com.ricky.www;public class CountCharacter {
public static void main(String[] args){
String content = "adafdadafdfdfadf";
String letterToFind = "a";
int result = countCharacter(content,letterToFind);
System.out.println(letterToFind + " 出现 " + result + " 次在 " + content + " 中.");
}
public static int countCharacter(String content,String ch){
String leave = content.replaceAll(ch,"");
int result = content.length() - leave.length();
return result;
}
}
问题三
把作业放到csdn让大家帮着做!
Exception in thread "main" java.lang.NoClassDefFoundError: FilterString (wrong n
ame: com/ricky/www/FilterString)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
什么原因?
wrong name: com/ricky/www/FilterString
名字错了?
java package ClassName
jjqwe520
一句话,不是有java API么?
为什么还不会解决这些简单的问题拉
那上面说的非常清楚
public class TestString {
public static void main(String[] args) {
String[] array = {"boy","zhang","ball","cat","hello"};
String str = "zahsalgkssapondfpQLNKaaDFG";
Pattern p ;
Matcher m ;
for(String s:array){
p = Pattern.compile("^b.*");
m = p.matcher(s);
while(m.find()){
System.out.println(m.group()); //以b 开头的字符串
}
}
p = Pattern.compile("a"); //设要查找的字符是 a
m = p.matcher(str);
int counter = 0; //计数
while(m.find()){
counter++;
}
System.out.println("a 出现的次数是 "+counter);//打印
}
}
问题一:public class TestString01{
public static void main(String[]args){
String[]str = {"b123", "a12", "d6", "f4", "b456", "r9"};
System.out.println("开头为b的字符串有:");
for(int i = 0; i < str.length; i++){
if(str[i].startsWith("b")){
System.out.println(str[i]);
}
}
}
}问题三public class TestString03{
public static void main(String[]args){
String s = "abacadaeaf";
int count = 0;
String[]str = new String[s.length()];
char[] c=s.toCharArray();
for(int i = 0; i < s.length(); i++){
str[i]= String.valueOf(c[i]);
if(str[i].equals("a")){
count++;
}
}
System.out.println("a 出现了 "+count+" 次");
}
}
package csdn;public class PrintBstart { /**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
String[] str = { "b123", "23ba", "bbc", "aab", "byyy" };
for (int i = 0; i < str.length; i++) {
if (str[i].startsWith("b")) {
System.out.println(str[i]);
}
} }}
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
String str="abcAbcAAAioi88A0";
int count=0;
for(int i=0;i<str.length();i++){
if(str.charAt(i)=='A'){//比如查找的是字符A
count++;
} }
System.out.println(count);
}}
package csdn; public class Find { /**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
String str="abcAbcAAAioi88A0";
int count=0;
for(int i=0;i <str.length();i++){
if(str.charAt(i)=='A'){//比如查找的是字符A
count++;
} }
System.out.println(count);
} }