如何删除字符串的一部分

Question

Given two strings, base and remove, return a version of the base string where all instances of the remove string have been removed (not case sensitive). You may assume that the remove string is of length 1 or more. Remove only non-overlapping instances, so with "xxx" removing "xx" leaves "x".

withoutString("Hello there", "llo") → "He there"
withoutString("Hello there", "e") → "Hllo thr"
withoutString("Hello there", "x") → "Hello there"

Why can't I use this code:

public String withoutString(String base, String remove)
{
    base.replace(remove, "");
    return base;
}

Answer 1

base.replace doesn't change the original String instance, since String is an immutable class. Therefore, you must return the output of replace , which is a new String .

      public String withoutString(String base, String remove) 
      {
          return base.replace(remove,"");
      }

Answer 2

String#replace() returns a new string, doesn't change the one it is invoked on, since strings are immutable. Use this in your code:

base = base.replace(remove, "")

Answer 3

Update your code:

public String withoutString(String base, String remove) {
   //base.replace(remove,"");//<-- base is not updated, instead a new string is builded
   return base.replace(remove,"");
}

Answer 4

Try following code

public String withoutString(String base, String remove) {
          return base.replace(remove,"");
      }

For Input :

base=Hello World   
remove=llo

Output :

He World

For more on such string operations visit this link.

Answer 5

Apache Commons library has already implemented this method,you don't need to write again.

Code :

 return StringUtils.remove(base, remove);