StringBuilder 拼接去除最後一個多餘字元
阿新 • • 發佈:2021-01-20
技術標籤:Java
如何去掉拼接字串時去掉最後一個多餘逗號:
public static void main(String[] args) { String str[] = {"hello", "awesome", "java", "world"}; StringBuffer buf = new StringBuffer(); for (int i = 0; i < str.length; i++) { buf.append(str[i]).append(","); } if (buf.length() > 0) { //方法一:deleteCharAt(效率級別:1最高)lastIndexOf(String str) :返回指定子字串最右邊出現的字串內的索引。 System.out.println(buf.deleteCharAt(buf.lastIndexOf(","))); //方法二:deleteCharAt(效率級別:2) System.out.println(buf.deleteCharAt(buf.length() - 1)); //方法三:substring(效率級別:3) System.out.println(buf.substring(0, buf.length() - 1)); //方法四:replace(效率級別:4) System.out.println(buf.replace(buf.length() - 1, buf.length(), "")); } }