String num1
## 获取字符串长度
num1.length()
## 获取索引 i 处的字符char
public class Test {
public static void main(String args[]) {
String s = "www.runoob.com";
char result = s.charAt(6);
System.out.println(result);
}
}
输出为: n
## 提取部分字符串
public class Solution {
public String reverseLeftWords(String s, int n){
return s.substring(n,s.length()) + s.substring(0,n);
}
}