算法基础

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1. 常用函数

// 字符串相关
String s;

// 字符串长度
int length = s.length();

// 获取指定index的字符
char c = s.charAt(index);

// 字符串转char数组
char[] cList = s.toCharArray();

// char数组转字符串
String s1 = new String(c);

// String数组转List
String[] s2  =new String[] {"hello", "world"};
List<String> l2 = Arrays.asList(s2);

// List转String数组
String[] s3 = l2.toArray(new String[0]);

// 获取子字符串
String childString = s.substring(startIndex, endIndex);