コードの断片を考えると、次のようになります。 StringBuilder sb = new StringBuilder ( ) ; Sb.append ("world"); Hello World を出力するコード部分はどれですか?
正解:A
The java.lang.StringBuilder.insert(int offset, char c) method inserts the string representation of the char argument into this sequence. The second argument is inserted into the contents of this sequence at the position indicated by offset. The length of this sequence increases by one.The offset argument must be greater than or equal to 0, and less than or equal to the length of this sequence.