[Java] substring()應用- substring_test.java

public class substring_test{
    public static void main(String args[]){
        String s = "abcdefg";
       
        System.out.println("0123456");
        System.out.println(s);
        System.out.println(s.length());
        System.out.println("0-2: "+s.substring(0,2));
        System.out.println("1-3: "+s.substring(1,3));
        System.out.println("2: "+s.substring(2));
   
    }
}

- - - - -
0123456  < 用來看清楚編號才加的
abcdefg   < 要截取的字串源
7
0-2: ab
1-3: bc
2: cdefg
- - - - -

切割字串取其中.

屬於 class String, 其中String 繼承 Object class.[1]

     java.lang.Object
        java.lang.String

String	substring(int beginIndex) Returns a new string that is a substring of this string.
String	substring(int beginIndex, int endIndex) Returns a new string that is a substring of this string.

其中, beginIndex就是要且取字串的開始,
一段字串像是一個字元陣列, 由 0 開始,
而endIndex 是結束編號, 會截取在此之前的字串.


[1] https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#substring%28int%29