从字符串中删除空格和特殊字符

Question

How can I format a string phone number to remove special characters and spaces?

The number is formatted like this (123) 123 1111

I am trying to make it look like this: 1231231111

So far I have this:

phone = phone.replaceAll("\\s","");
phone = phone.replaceAll("(","");

The first line will remove the spaces. Then I am having trouble removing the parentheses. Android studio underlines the "(" and throws the error unclosed group .

Answer 1

您可以删除除数字之外的所有内容：

phone = phone.replaceAll("[^0-9]","");

Answer 2

To remove all non-digit characters you can use

replaceAll("\\D+",""); \\ \D is negation of \d (where \d represents digit) 

If you want to remove only spaces, ( and ) you can define your own character class like

replaceAll("[\\s()]+","");

Anyway your problem was caused by fact that some of characters in regex are special . Among them there is ( which can represent for instance start of the group . Similarly ) can represent end of the group.

To make such special characters literals you need to escape them. You can do it many ways

• "\\\\(" - standard escaping in regex
• "[(]" - escaping using character class
• "\\\\Q(\\\\E" - \\Q and \\E create quote - which means that regex metacharacters in this area should be treated as simple literals
• Pattern.quote("(")) - this method uses Pattern.LITERAL flag inside regex compiler to point that metacharacters used in regex are simple literals without any special meaning

Answer 3

你需要在正则表达式中转义(因为它表示元字符（组的开头）。相同) 。

phone = phone.replaceAll("\\(","");

Answer 4

public static void main(String[] args){
    // TODO code application logic here
  String str = "(test)";
  String replaced= str.replaceAll("\\(", "").replaceAll("\\)", "");
  System.out.println(replaced);


}