java中String类的一些常用方法

方法描述public String(char[] value)用字符数组value创建一个String对象public String(char chars[], int x, int n)用字符数组以x开始的n个字符创建一个String对象public int length()获取字符串长度public char charAt(int index)获取字符串某一位置的字符public String substring(int beginIndex) / public String substring(int beginIndex, intendIndex)获取字符串的子串public int compareTo(String str) / public int compareToIgnoreCase (String str) / public boolean equals(Object obj) / public boolean equalsIgnoreCase(String str)字符串的比较public int indexOf(String str) / public int indexOf(String str, intfromIndex) / public int lastIndexOf(String str) / public int lastIndexOf(String str, intfromIndex)查找子串在主串中的位置public String toLowerCase() / public String toUpperCase()字符串大小写转换String trim()字符串去掉两端空格String[] split(String str)将字符串分割成字符串数组static String valueOf(xxx xx)基本类型转换为字符串public String replace(char oldChar, charnewChar) / public String replaceFirst(String regex,String replacement) / public String replaceAll(String regex,String replacement)替换字符串