How do i write a regular expression in Java which given a certain pattern, extracts the value after it and stores it in an array. If there is no value in after that pattern it should add a blank (i.e "") to the array.
As an example for pattern &&, I should get the following inputs and outputs:
input=&&&&&&&&&&
o/p=["","","",""];
input=&&A&&123&&B&&985
o/p=["A",123,B,985];
input=&& && &&A&&488
o/p=["","","A","488"]
You can set the delimiter on a Scanner and then iterate through its values.
public String[] getTokens() {
LinkedList<String> list = new LinkedList<String>();
Scanner s = new Scanner(input).useDelimiter("\\&\\&");
while(s.hasNext()) {
list.add(s.next());
}
String[] a = new String[list.size()];
return list.toArray(a);
}
You can try using split. You can omit the first result and use the rest from the output of the following code.
String testStr = "&&A&&123&&B&&985";
String[] splitString = testStr.split("(&&)");
for (String token : splitString) {
System.out.println(token);
}
public static void main (String[] args) {
String str = "&&A&&&&&&D&&123&&XX&&";
String delimiters = "([&]{2})";
// analyzing the string
String[] tokensVal = str.split (delimiters);
System.out.print ("[");
for (String token: tokensVal) {
// Print empty and space tokens
if(token.isEmpty () || token.equals (" ")){
System.out.print ("\"\",");
} else {
System.out.print (token + ",");
}
}
System.out.print ("]");
}
O/P ["",A,"",D,]
There is one problem is here when there is only & in whole string eg "&&&&&&" then you have to handle it in special way.
I apologize that I don't know Java, but assuming it has the ability to replace and capture, you could do this in two steps.
First would be to replace any occurrence of
&&
with
&&\s
Second would be to iterate through the captured results returned from
&{2}([^&]+)
and trim the excess space off any results
