How to check if a text contains an element of an ArrayList - arraylist

Question

I have a text and an array list. I would like to check if my text contains any element in the ArrayList, and if he does find it, to replace the space between two words with "%".
Here's my code :
public static boolean stringContainsItemFromList(String text, ArrayList<String> list)
{
for (String i: list)
{
if (text.contains(list[i]))
{
text.replaceAll(" ", "%");
System.out.println("done");
return true;
}
}
return false;
}
It gives me this error: string cannot be converted to int for the line if (text.contains(list[i])). Any idea how else can I proceed?

Answer 1

i is a String. In that case list[i] does not make sense, since i inside of list[i] should be an index, which is an integer (e.g. list[0], list[1], but can not be list["hello"]).
So if you want to check that your text contains a String from list, you can use
if(text.contains(i))
Also, be aware that your result of
text.replaceAll(" ", "%");
is being ignored. If you want to keep the altered text, you can do that by storing the result of the replace into a new, separate variable.

Answer 2

Your error is because i is a string and you're using it as a int
public static boolean stringContainsItemFromList(String text, ArrayList<String> list)
{
for (String i: list) // HERE: i is an element of the list, not the index!
{
if(text.contains(list[i])) // HERE: list[string] -> error!
{
text.replaceAll(" ", "%");
System.out.println("done");
return true;
}
}
return false;
}
replace text.contains(list[i]) for text.contains(i) and try to use more descriptive var names :)

Answer 3

Something makes me believe, you actually need this !
public static boolean stringContainsItemFromList(String text, ArrayList<String> list)
{
boolean flag = false;
for (String i: list) {
if(text.contains(i)) {
text = text.replaceAll(i, "%");
flag = true;
}
}
System.out.println(text);
System.out.println("done");
return flag;
}

Answer 4

ArrayList<String> list is not an array, it is a list. So you can get the elements of list by calling get() method.
e.g.
list.get(0) // returns the first element of the list
Also
for (String i: list) {
// ...
}
is a foreach loop, a different version of
for(int x=0; x<list.size(); x++) {
// ...
}
i corresponds to list.get(x)
You should change text.contains(list[i]) to text.contains(i) because i stands for list.get(x)
Q: How to check if a text contains an element of an ArrayList
After fixing the error you'll see that the variable text has not changed. Because in Java strings are immutable and replaceAll() method returns a new string. So you should assign the new value to the text variable:
text = text.replaceAll("\\s", "%");
Here is the corrected version of the stringContainsItemFromList() method:
public static boolean stringContainsItemFromList(String text, List<String> list)
{
for (String i: list) {
if(text.contains(i)) {
text = text.replaceAll("\\s", "%");
System.out.println("done");
System.out.println(text);
return true;
}
}
return false;
}