关于Java中String类的相关方法

• 判断字符串中是否有特殊要求的字符

String city = "北京市";
System.out.println(city.contains("市"));
----------------------------------------
结果: true

String city = "北京";
System.out.println(city.contains("市"));
----------------------------------------
结果: false

• 替换字符串中特定的字符

String city = "北京市";
System.out.println(city.replace("市", ""));
-------------------------------------------
结果: 北京

String city = "北京";
System.out.println(city.replace("市", ""));
-------------------------------------------
结果: 北京