CODEWITHSUNDEEP
javaandroidsubstring
Si8
Si8

Reputation: 9225

Get certain substring from a string value

I have the following dates:

"Friday, January 31",
"Wednesday, February 12",
"Monday, February 17",
"Wednesday, March 5",

I want to set up a string function where I am given the number always:

31
12
17
5

I started with this function:

String strCheck = suspendedDates[i];
int pos = strCheck.length();
int pos2 = strCheck.indexOf(" ");

I am stuck right now, because how does it know which " " is it?

Can someone help me with the function.

Upvotes: 0

Views: 138

Answers (6)

Ross Drew
Ross Drew

Reputation: 8246

Get the substring from the end. Instead of trying to figure out locations

strCheck.substring(strCheck.length()-2);

This will take the last two characters. Then just do a trim() in case it's a single character to remove the space:-

strCheck.substring(strCheck.length()-2).trim();

Alternative

The other option as mentioned is to do a lastIndexOf() on the String with a space (" ") as an argument which will search backward from the end of the String till it finds the space. But as the number can always be extracted in 2 character spaces, I see no reason to do 2 character compares every time you want to extract a known size String (2) in a known location (length()-2) in order to retrieve the location that you already know.

Upvotes: 2

Jigar Joshi
Jigar Joshi

Reputation: 240860

use lastIndexOf() instead of indexOf()

final String str = "Friday, January 31";
System.out.println(str.substring(str.lastIndexOf(" ")));

Upvotes: 4

StoopidDonut
StoopidDonut

Reputation: 8617

I had to post it; since this is a date I would go with Date parse to allow an additional check on the format of the inputs:

An alternative way:

SimpleDateFormat format = new SimpleDateFormat("EEEE, MMMM DD");
Calendar cal = Calendar.getInstance();

cal.setTime(format.parse("Friday, January 31"));
System.out.println(new SimpleDateFormat("DD").format(cal.getTime()));

2nd SimpleDateFormat("DD") is used instead of deprecated getDate().

Upvotes: 2

Vamshi
Vamshi

Reputation: 520

You can use something like this:

 String str = "Friday, January 31";
 Scanner s = new Scanner(s);
 s.useDelimiter( "\\D+" );
 while ( s.hasNextInt() ){
   s.nextInt(); // get int
 }

Upvotes: 1

nachokk
nachokk

Reputation: 14413

As an alternative of @JigarJoshi answer you can use a regex if you don't mind, removing all non-number characters.

String result = dateString.replaceAll("[^\\d]+","");

Upvotes: 2

Drifter64
Drifter64

Reputation: 1123

If you are trying to divide the string into parts for parsing, i suggest using String.split(" "), look at the javadocs and the internet for lots of nice examples of this in use! :)

Upvotes: 1

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