如何隔离String的组件？

Question

I have a method that returns a String . That string called contact is made of multiple smaller strings. Those smaller strings were parameters to that method.

exemple :

String contact = id + " " + name + " " + telNum;
return contact;

Now I have another method that takes contact as a parameter but that needs to return ONLY name.

So my question is how can I isolate that smaller string name from the whole string contact?

Answer 1

Use

String[] splits = contact.split(" ");
String name = splits[1];

Answer 2

The answer of Viswanath shows how to retrieve the name from the string using string functions.

As an alternative you could consider to create a Contact class which holds the information:

 public class Contact {
     public String id;
     public String name;
     public String tel;

     public String toString() { return id + " " + name + " " + telNum; }
 }

and then pass a Contact object around instead of the string which represents the contact .

Answer 3

If id and telNum are two integer/long values you can do something like

int startIndex = contact.indexOf(" ");
int endIndex = contact.lastIndexOf(" ");
String name = contact.substring(startIndex, endIndex).trim();

It should be easier if your string has separators, like comma.

Ex.:  String contact = id + ", " + name + ", " + telNum;

In this case you could do the same of above but searching the index of "," or of ", ".

Answer 4

如果您的ID只有号码，而电话号码以+或任何数字开头，那么您可以轻松地从中获取名称。

Answer 5

String name = contact.substring(contact.indexOf(" ", 0)+1, contact.indexOf(" ", contact.indexOf(" ", 0)+1);