示例 : 获取字符
charAt(int index)获取指定位置的字符
package cm.po;
public class Sder {
public static void main(String[] args) {
String sentence = "累死我第三级拉丝粉卢卡库分类拉开发";
char c = sentence.charAt(3);
System.out.println(c);
}
}
示例 : 获取对应的字符数组
toCharArray()
获取对应的字符数组
package cm.po;
public class Sder {
public static void main(String[] args) {
String sentence = "累死我第三级拉丝粉卢卡库分类拉开发";
char[] cs = sentence.toCharArray(); //获取对应的字符数组
System.out.println(sentence.length() == cs.length);
}
}

示例 : 截取子字符串
package cm.po;
public class Sder {
public static void main(String[] args) {
String sentence = "累死我第三级拉丝粉卢卡库分类拉开发";
//截取从第3个开始的字符串 (基0)
String subString1 = sentence.substring(3);
System.out.println(subString1);
//截取从第3个开始的字符串 (基0)
//到5-1的位置的字符串
//左闭右开
String subString2 = sentence.substring(3,5);
System.out.println(subString2);
}
}