java中判断是否是字母

记录一个方法，用来判断一个字串中字符是否全为字母
 
public class MainClass {
    public static void main(String[] args){   
        
        String str = "hhhggdxszfff";  
        boolean is_boolean = isPhonticName(str);
        System.out.println(is_boolean);
}
 
    
    public static boolean isPhonticName(String str) {
        char[] chars=str.toCharArray();
        boolean isPhontic = false;
        for(int i = 0; i < chars.length; i++) {
            isPhontic = (chars[i] >= &#39;a&#39; && chars[i] <= &#39;z&#39;) || (chars[i] >= &#39;A&#39; && chars[i] <= &#39;Z&#39;);
            if (!isPhontic) {
                return false;
            }
        }
        return true;
    }
 
}