문자열 : 포함여부

String str = "I LOVE MYSELF"

• charAt(int)

str.charAt(5) = 'E'

 

• indexOf('str')

str.indexOf("E") = 5

 

• lastIndexOf('str')

str.lastIndexOf("E") = 10

 

• contains('str')

 
str.contains("SELF") = true

 

• startsWith('str')

str.startsWith("LOVE") = false

 

• endsWith('str')

str.endsWith("SELF") = true

 

• isEmpty()

str.isEmpty() = false

 

• equals('str')

str = "KOREA";

str.equals("KOREA") = true

str.equals("korea") = false
=> str.equalsIgnoreCase("korea") = true