How would I be able to access specific strings with and array list?
List<String> myList = new ArrayList<String>();
myList.Add("Hi");
myList.Add("Pizza");
myList.Add("Can");
So if I did that and then I do:
for (String s : myList)
if (s == "Hi")
system.out.println("Hello"):
It would not print "Hello".
I need the size to change and see if the string exists but I can't seem to get this to work, any ideas?
- Objects in Java are compared using equals(), and String is an Object in Java, so it follows the same rule.
- == will be used to compare primitive or to check if two or more Object Reference Variables are pointing to the same Object on the heap or not.
- So you should use equals() or equalsIgnoreCase() (if case doesn't matters) to compare the String Objects.
for (String s : myList){
if (s.equals("Hi"))
system.out.println("Hello");
}
if (s == "Hi")
change it to
if (s.equals("Hi"))
It is always better to use equals() while comparing objects than using == (except String literals)
== compares reference equality. equals() compares object content equality.
You should write below code
for (String s : myList)
if (s.equals("Hi"))
system.out.println("Hello"):
You should use .equals() method it will check the value of the string while == checke Object reference.
Method name is add(object) not `Add(). Here is an another answer
List<String> myList = new ArrayList<String>();
myList.add("Hi");
myList.add("Pizza");
myList.add("Can");
// method 1
if( myList.contains("Hi")) {
System.out.println("Found");
}
// method 2
for( String word : myList ) {
if( word.equals("Hi")) {
System.out.println("found");
// break the loop to avoid continues iteration
break;
}
}
Why not use List.contains()?
if (myList.contains("Hi"))
system.out.println("Hello");
==to test non-primitive objects for equality, generally. OverrideObject.equals()meaningfully and use it.list.contains("Hi")can also be used.