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Check if input is any of the values in an array [duplicate]

This question already has answers here:
How do I determine whether an array contains a particular value in Java?
(30 answers)
Closed 2 years ago.
I want to be able to check if the string input matches any of the strings in array, and then run only if it matches any of the strings.
String[] list = {"hey","hello"};
if (input == anyofthestringsinarray) {
}
Thought something like if(input.equalsIgnoreCase(list)) {} could work, but dont. Any tips?

Try this:
public static void stringContainsItemFromList(String inputStr, String[] items)
{
for(int i =0; i < items.length; i++)
{
if(inputStr.contains(items[i]))
{
// if present do something
}
}
}

Java - Why is the output of this enum array null? [duplicate]

This question already has answers here:
Default or initial value for a java enum array
(5 answers)
Can we assume default array values in Java? for example, assume that an int array is set to all zeros?
(4 answers)
Closed 4 years ago.
I created an enum array like this:
enum MyEnums {
FIRST, SECOND, THIRD, FOURTH;
}
public class MyEnumsTest {
public static void main(String[] args) throws Exception {
MyEnums[] myEnums = new MyEnums[4];
for(int i = 0; i< myEnums.length; i++) {
System.out.println(myEnums[i]);
}
}
}
But why is the output null, null, null and null? And how can I get the element by myEnums[i].FIRST?

What you're doing here is creating an array of MyEnums, and the default value is null (you haven't set the values in the array).
If you wanted to print out the enum values you can use the values() method:
for(MyEnums en : MyEnums.values()) {
System.out.println(en);
}
or (more like your original code)
for(int i = 0; i < MyEnums.values().length; i++) {
System.out.println(MyEnums.values()[i]);
}
This prints:
FIRST
SECOND
THIRD
FOURTH

Why does my switch case work here, but if does not? [duplicate]

This question already has answers here:
How do I compare strings in Java?
(23 answers)
Closed 4 years ago.
I am learning how to use Lists, and in my following example the switch case works but (what I deem as) the equivalent if statement does not. Can you tell me why?
public class Kapitel14 {
public static void main(String[] args) {
ArrayList<String> testList = new ArrayList<String>();
testList.add("Cousin");
testList.add("Doof");
testList.add("Dorf");
testList.add("Dortmund");
testList.add("Franz");
System.out.println(listCount(testList));
}
public static int listCount(ArrayList<String> newList) {
int capDCounter = 0;
for (String element : newList) {
String firstLetter = Character.toString(element.charAt(0));
switch (firstLetter) {
case ("D"):
capDCounter++;
break;
default:
continue;
}
//if I use this instead it returns wrong results:
//if (firstLetter == "D")
// capDCounter++;
}
return capDCounter;
}

Use
if (firstLetter.equals("D"))
capDCounter++;
instead of
if (firstLetter == "D")
capDCounter++;
.equals() method should be used here as you want to compare the values of strings.

simple String example [duplicate]

This question already has answers here:
How do I compare strings in Java?
(23 answers)
Closed 5 years ago.
i have the following piece of code but i could not detect why there is no output
when i debug it , the control flow is never goes inside for loop but i cannot figure out why
could anyone please help me ?
here is my code
public class DealWithStrings {
ArrayList<String> container = new ArrayList<>();
public void printDuplicate() {
String string = "aaabed";
String[] res = string.split("");
for (int i = 1; i < string.length(); i++) {
if (res[i] == res[i - 1]) {
container.add(res[i]);
}
}
for (String s : container) {
System.out.println(s);
}
}
public static void main(String[] args) {
DealWithStrings d = new DealWithStrings();
d.printDuplicate();
}
}

Compare String using .equals, not ==
Instead of
if(res[i]==res[i-1])
Use
if(res[i].equals(res[i-1]))
== will evaluate to true if the objects are the same, and in this case they never are. .equals will check if the contents of the Strings (the actual text) are the same.

Replace your code '==' operator with '.equals()' method, because ,
'==' equal operator compares the reference of the two characters in memory, whereas you need to check 'contents' at that reference.
And .equals method is overridden to check the content for Strings.
for (int i = 1; i < string.length(); i++) {
if (res[i].equals(res[i - 1])) {
container.add(res[i]);
}
}

Java - search a string in string array [duplicate]

This question already has answers here:
How do I determine whether an array contains a particular value in Java?
(30 answers)
Closed 6 years ago.
In java do we have any method to find that a particular string is part of string array.
I can do in a loop which I would like to avoid.
e.g.
String [] array = {"AA","BB","CC" };
string x = "BB"
I would like a
if (some condition to tell whether x is part of array) {
do something
} else {
do something else
}

Do something like:
Arrays.asList(array).contains(x);
since that return true if the String x is present in the array (now converted into a list...)
Example:
if(Arrays.asList(myArray).contains(x)){
// is present ... :)
}
since Java8 there is a way using streams to find that:
boolean found = Arrays.stream(myArray).anyMatch(x::equals);
if(found){
// is present ... :)
}

You could also use the commons-lang library from Apache which provides the much appreciated method contains.
import org.apache.commons.lang.ArrayUtils;
public class CommonsLangContainsDemo {
public static void execute(String[] strings, String searchString) {
if (ArrayUtils.contains(strings, searchString)) {
System.out.println("contains.");
} else {
System.out.println("does not contain.");
}
}
public static void main(String[] args) {
execute(new String[] { "AA","BB","CC" }, "BB");
}
}

This code will work for you:
bool count = false;
for(int i = 0; i < array.length; i++)
{
if(array[i].equals(x))
{
count = true;
break;
}
}
if(count)
{
//do some other thing
}
else
{
//do some other thing
}