##String常用方法（上）
public class Test {public static void main(String[] args) {String letters = " abEf ";System.out.println(letters.length());//返回字符长度System.out.println(letters.equals(" abEf "));//判断字符串是否相等System.out.println(letters.equalsIgnoreCase(" abef "));//忽略大小写，判断字符串是否相等System.out.println(letters.startsWith(" a"));//判断字符串是否以XXX开头System.out.println(letters.endsWith("Ef "));//判断字符串是否以XXX结尾System.out.println(letters.trim());//返回去掉两端空格后的字符串System.out.println(letters.replaceAll(" ","#"));//将字符串中的" "全部替换为"#"System.out.println(letters.charAt(1));//获取字符串中第X个字符，从0开始letters = "110#119#112";String [] mobiles = letters.split("#");//将字符串按"#"切割成多个字符串，等价于{"110","119","112"}for (String mobile : mobiles) {System.out.println(mobile); //for each循环输出}}
}