By using Jsoup I parse HTML from a website to populate an ArrayList
with what I needed to fetch from the website. So now I have an ArrayList
that is filled with strings. I want to find the index in that list that contains a certain string. For example, I know that somewhere in the list, in some index, there is the string(literal) "Claude" but I can't seem to make any code that finds the index that contains
"Claude" in the ArrayList
... here is what I have tried but returns -1
(not found):
ArrayList < String > list = new ArrayList < String > ();
String claude = "Claude";
Document doc = null;
try {
doc = Jsoup.connect("http://espn.go.com/nhl/team/stats/_/name/phi/philadelphia-flyers").get();
} catch (IOException e) {
e.printStackTrace();
}
for (Element table: doc.select("table.tablehead")) {
for (Element row: table.select("tr")) {
Elements tds = row.select("td");
if (tds.size() > 6) {
String a = tds.get(0).text() + tds.get(1).text() + tds.get(2).text() + tds.get(3).text() + tds.get(4).text() + tds.get(5).text() + tds.get(6).text();
list.add(a);
int claudesPos = list.indexOf(claude);
System.out.println(claudesPos);
}
}
}
The index of a particular element in an ArrayList can be obtained by using the method java. util. ArrayList. indexOf().
You can get the character at a particular index within a string by invoking the charAt() accessor method. The index of the first character is 0, while the index of the last character is length()-1 . For example, the following code gets the character at index 9 in a string: String anotherPalindrome = "Niagara.
The indexOf() method is used to get the index of the first occurrence of an element in an ArrayList object. The element whose index is to be returned. Return Value: The index of the first occurrence an element in ArrayList, or -1 if the element does not exist.
ArrayList. contains() method can be used to check if an element exists in an ArrayList or not. This method has a single parameter i.e. the element whose presence in the ArrayList is tested. Also it returns true if the element is present in the ArrayList and false if the element is not present.
You're confusing String.indexOf
and List.indexOf
. Considering the following list:
list[0] = "Alpha Bravo Charlie"
list[1] = "Delta Echo Foxtrot"
list[2] = "Golf Hotel India"
list.indexOf("Foxtrot") => -1
list.indexOf("Golf Hotel India") => 2
list.get(1).indexOf("Foxtrot") => 11
So:
if (tds.size() > 6) {
// now the string a contains the text of all of the table cells joined together
String a = tds.get(0).text() + tds.get(1).text() + tds.get(2).text() +
tds.get(3).text() + tds.get(4).text() + tds.get(5).text() + tds.get(6).text();
// now the list contains the string
list.add(a);
// now you're looking in the list (which has all the table cells' items)
// for just the string "Claude", which doesn't exist
int claudesPos = list.indexOf(claude);
System.out.println(claudesPos);
// but this might give you the position of "Claude" within the string you built
System.out.println(a.indexOf(claude));
}
for (int i = 0; i < list.size(); i += 1) {
if (list.get(i).indexOf(claude) != -1) {
// list.get(i).contains(claude) works too
// and this will give you the index of the string containing Claude
// (but not the position within that string)
System.out.println(i);
}
}
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