不使用正则表达式 匹配字符串（字母）

package a_不常用类;
public class 正则表达式_no {
public static void main(String[] args){
String str = "asd&sdklkl";
comp(str);
// char ch = 'a';
// System.out.println(ch+0);
// System.out.println('z'>'x');
// System.out.println('A'+0);
// System.out.println('Z'+0);

}
public static void comp(String str){
int index = 0;
char[] chs = str.toCharArray();
String[] sts = null;
StringBuilder sb = null;
int len = chs.length;
sts = new String[len/2+1];
boolean newChar = false;
for(int i=0;i char c = chs[i];
if(i==0){
sb = new StringBuilder();
if(check(c))
sb.append(c);
}else{
if(check(c)){
if(newChar){
sb = new StringBuilder();
sb.append(c);
newChar = false;
}else{
sb.append(c);
if(i==len-1)
sts[index++] = sb.toString();
}

}
else{
if(newChar)//特殊字符
newChar = true;//新建字符串
else{
sts[index++] = sb.toString();
newChar = true;//新建字符串
}
}
}
}
System.out.println("符合的字符串有:"+index+"个");
for(int i=0;i System.out.println("依次为:"+sts[i]);
}
}
private static boolean check(char c){
return 'a'<=c&&c<='z'||('A'<=c&&c<='Z');
}
}