logo
down
shadow

Check if hash map key is present before retrieving value


Check if hash map key is present before retrieving value

By : Hâmzâ MöÛddene
Date : November 19 2020, 03:01 PM
around this issue Given I am checking my hashmap as follows , Before Java 8, you have to explicitly do the check :
code :
String firstName = map.get(UserDetail.FIRST_NAME);

// null guard
if (firstName != null){
   // invoke a method on firstName 
}
String firstName = map.getOrDefault(UserDetail.FIRST_NAME, "");
Optional<String> optional = Optional.of(map.get(UserDetail.FIRST_NAME));
optional.ifPresent((s)->myProcessing());
Optional.of(map.get(UserDetail.FIRST_NAME))
        .ifPresent((s)->myProcessing());


Share : facebook icon twitter icon
How to check if a specific key is present in a hash or not?

How to check if a specific key is present in a hash or not?


By : Kamil Konieczny
Date : March 29 2020, 07:55 AM
it should still fix some issue I want to check whether the "user" key is present or not in the session hash. How can I do this? , Hash's key? method tells you whether a given key is present or not.
code :
session.key?("user")
How to check if specific value is present in a hash?

How to check if specific value is present in a hash?


By : Justhing Yus
Date : March 29 2020, 07:55 AM
around this issue Hash includes Enumerable, so you can use the many methods on that module to traverse the hash. It also has this handy method:
code :
hash.has_value?(value_you_seek)
hash.key(value_you_seek)
Check hash element present and return a value

Check hash element present and return a value


By : Matt Busby Dearden
Date : March 29 2020, 07:55 AM
fixed the issue. Will look into that further if I have an array of hashes like below(in JSON) and I want to check if an Id exists.
code :
a =  [ { "Id" => 14, "Currencies" => { "48" => 840, "410" => 840, "978" => 826 } }, { "Id" => 19 } ]
h = a.detect {|i| i["Id"] == 14 && i.has_key?("Currencies") }
h["Currencies"].values unless h.nil?
# => [840, 840, 826]
Check if hash is present, if not then add hash

Check if hash is present, if not then add hash


By : Adarsh Kumar
Date : March 29 2020, 07:55 AM
around this issue I'm trying to detect if there is a hash present and if not then add a hash to the URL using. I've read multiple posts on stack trying to find the solution but I can't seem to get my code to work. , Set the hash using location.hash:
code :
if(window.location.hash == ''){
    location.hash = '#yourhash';
}
How to check if a hash key is present in the hash by matching any letter/number for a character {say X}

How to check if a hash key is present in the hash by matching any letter/number for a character {say X}


By : Phil Soden
Date : March 29 2020, 07:55 AM
I hope this helps you . I have a hash, say "Identifier" with keys such as FACD,BDCD,DDSE,CDSD. I would like to search if the key "FXXD" is present in the hash "Identifier" by considering X to match any alphanumeric. In this scenario, it should come back with found as "FXXD" matches "FACD" considering X can be anything. , To select keys that satisfy a pattern
code :
my @spec_keys = grep { /F..D/ } keys %identifier;
Related Posts Related Posts :
  • Interrupt CompletableFuture with default value
  • Eclipse - Choosing servers in "Run on server" vs setting "Target Runtime"
  • Spring JPA doesn't validate bean on update
  • How is takeWhile different from filter?
  • Spring Scheduled Cron jobs firing at wrong time
  • JFrame window resizing on every compile. Different results every time
  • Kotlin unresolved reference :add after converting from Java code
  • How to use Neo4j APOC method " apoc.export.csv.query(query,file,config)" in Java program
  • Regex to include all spanish characters and number
  • Parsing and Mapping a JSON Object with Dynamic Properties
  • Which approach to building domain objects in Spring MVC is more correct?
  • Java Long Min and Max not exact as mentioned in docs
  • Selenium opens new tab after SendKeys
  • How to sort a large array of ints?
  • FitNessse Test can not find Fixture
  • Including Signed Libraries in Executable JAR with Maven
  • If and Else statement run on second iteration of while loop
  • Change class of disabled tab on change of dropdown value
  • Junit5 @ParameterizedTest How to pass array as one of parameter
  • Text message not being sent to a list of numbers but is sent when just one number is specified
  • Spring mapped servlet not called in jetty-maven-plugin
  • How to pace the consumption of a sqs queue using spring integration
  • Autowiring Not getting disabled using xml configuration
  • Maze solve and shortest path with Java BFS
  • Spinner updating only on user actions
  • Why are Java rules for protected access such as they are?
  • Modify parameter of method by value in annotation aspectJ
  • How to send sensitive data to a Liferay portlet from outside the Liferay portal
  • Does a server connection stay open if created inside a method?
  • JAR manifest Class-Path, use folder instead of jar
  • How to do a bulk update in Firestore
  • ItemArray.checklist.add() not appending string to ArrayList
  • How to move something on screen without other picture staying there
  • SpringBoot : No matching bean found exception
  • Implementing the Clonable interface, but don't have to override the clone() method
  • how can i get this code to choose a random word once from each array to print a sentence?
  • Static class to get connections from connection pool
  • Unable to start Chrome browser with user profile in Selenium
  • How to pass a object to be created as a parameter for a method in Java?
  • How to retry with hystrix
  • Loading key to KeyStore fails on Android Oreo
  • Spring+Velocity unsuccessful attempts to save object
  • Private constructor in Kotlin
  • Jetty:run fails with NoSuchMethodError with Spring 5
  • Cannot upload my Web Applicartion in Jboss7 EAP7 EAP
  • How to load a certificate from "Credential storage"?
  • Call Genexus procedure stub in Java environment
  • JavaFX clipping produces a 'lottery scratch ticket'-Effect
  • Using DateTimeFormatter on january first cause an invalid year value
  • Get all the output from Watson conversation using java
  • Java unable to open main class and jar file
  • How to override @override method from activity into another class
  • Adding Runtime VM parameters to intellij for Java 9
  • Java IBM MQ Client connected but not getting messages from queue
  • Questions of Tomcat SSL configuration
  • Stale JNLP files for <extension> (since Java 9?)
  • Properly set (system) properties in JUnit 5
  • Spring MVC Model within POST Method is empty
  • VSTS buildagent: Java 9
  • java.lang.NumberFormatException: For input string: "id" for Hibernate
  • shadow
    Privacy Policy - Terms - Contact Us © voile276.org