高分悬赏：Java语言字符串怎么做减法？比如

Question

高分悬赏：Java语言字符串怎么做减法？比如
abcdefg - defg = abc
aaaaaa - a = aaaaa
abbbbbb - a = bbbbbb

Answer 1

代码如下:

str1="abcd";
str2="cd";
str3=str1.replaceAll(str2,"");
//str3="ab"

Answer 2

写个方法 首先判断要减去的字符串在被减数中是否存在，如果有获得这个字符串的下标（比如说lastindexof）然后用substring给他截取成两部分再合在一起，例如abc-b截成两个字符串a和c；

Answer 3

String aaaaaa = "bbbbbbabbb";
String a = "bab";
String hcStr= "";
Integer res = aaaaaa.indexOf(a);
Integer length = a.length();
Integer lengthAll = aaaaaa.length();
String endaaa = "";
if(res == 0){
        endaaa = aaaaaa.substring(res+length,lengthAll);
}else {
        hcStr = aaaaaa.substring(0,res);
        endaaa = hcStr+aaaaaa.substring(res+length,lengthAll);
}

System.out.println(endaaa);