Java 8 Lambda Kullanimi

Parametreli methodlarda lambda kullanimi
(argument-list) -> {body}

Asagidaki ornekte ilk once klasik yontemle instance olusturarak, daha sonra ise lambda ile gosterim yapilmistir.
@FunctionalInterface
interface ExampleInterface{
        public int exampleMedhot(int a1, int a2);
}

public class Test1 {
        public static void main(String[] args){
     ExampleInterface e1 = new ExampleInterface() {
             
             @Override
             public int exampleMedhot(int a1, int a2) {
          return a1 + a2;
             }
     }; 
     
    System.out.println(e1.exampleMedhot(3, 5));
    
    
    ExampleInterface e2 = (int a1, int a2) -> {
            return a1 + a2;
    };
    
    System.out.println(e2.exampleMedhot(3, 5));
        }
}

Metod parametre almadigi zaman ise asagidaki sekilde lambda kulanilir.


@FunctionalInterface
interface ExampleInterface{
        public int exampleMedhot();
}

public class Test1 {
        public static void main(String[] args){
    
     ExampleInterface e2 = () -> {
  return 8;
     };
     
     System.out.println(e2.exampleMedhot());
        }
}

Arrays.asList("a1", "a2", "a3").forEach(item -> {
  System.out.println(item);
     });</pre>

JS Callback and JS Promise

JS Callback

function adimiYaz(ad){console.log("Gamze");}

function soyadimiYaz(ad){console.log("Sen");}

function adimiYaz(ad){console.log(ad);}

function soyadimiYaz(soyad){console.log(soyad);}

adimiYaz("gamze");

gamze

adimiYaz("gamze"); soyadimiYaz("sen");

gamze

sen

function adimiYaz(ad){ setTimeout(function(){ console.log(ad);}, 2000);}

function soyadimiYaz(soyad){setTimeout(function(){console.log(soyad);}, 1000);}

adimiYaz("gamze"); soyadimiYaz("sen");

 sen

gamze

function adimiYaz(ad){ setTimeout(function(){ console.log(ad);}, 4000);}

function soyadimiYaz(soyad){setTimeout(function(){console.log(soyad);}, 1000);}

adimiYaz("gamze"); soyadimiYaz("sen");

 sen

gamze

function adimiYaz(ad, callback){ setTimeout(function(){ console.log(ad); callback("sen"); }, 4000);}

function soyadimiYaz(soyad){setTimeout(function(){console.log(soyad);}, 1000);}

adimiYaz("Gamze", soyadimiYaz);

 Gamze

sen

 JS Promise

 let sonuc = false;

let islem = new Promise(function(resolve, reject){

                if(sonuc){

               resolve("Basarili");

  }else{

               reject("Hatali");

  }

});

islem.then(function(data){

                console.log(data);

}).catch(function(data){

                console.log(data);

});

Hatali

 let req1 = new Promise(function(resolve, reject){

                setTimeout(function(){

               resolve("First");

  }  ,2000);

});

let req2 = new Promise(function(resolve, reject){

                setTimeout(function(){

               reject("Second");

  } , 3000);

});

Promise.all([req1, req2]).then(function(results){

                console.log("Then: ", results);

}).catch(function(err){

                console.log("Catch: ", err);

});

 Catch:  Second

 let req3 = new Promise(function(resolve, reject){

                setTimeout(function(){

               resolve("First");

  }  ,2000);

});

let req4 = new Promise(function(resolve, reject){

                setTimeout(function(){

               reject("Second");

  } , 3000);

});

Promise.race([req3, req4]).then(function(results){

                console.log("Then: ", results);

}).catch(function(err){

                console.log("Catch: ", err);

});

Then:  First

Ornekler cesitli sitelerden alinmistir.