Complete the exercise CrazyLambdas.java

Author: tboychuk

crazy-lambdas/src/main/java/com/bobocode/CrazyLambdas.java

@@ -1,6 +1,7 @@
 package com.bobocode;
 
 import java.math.BigDecimal;
+import java.util.concurrent.ThreadLocalRandom;
 import java.util.function.*;
 
 public class CrazyLambdas {
@@ -11,7 +12,7 @@ public class CrazyLambdas {
      * @return a string supplier
      */
     public static Supplier<String> helloSupplier() {
-        throw new UnsupportedOperationException("It's your job to implement this method"); // todo
+        return () -> "Hello";
     }
 
     /**
@@ -20,7 +21,7 @@ public static Supplier<String> helloSupplier() {
      * @return a string predicate
      */
     public static Predicate<String> isEmptyPredicate() {
-        throw new UnsupportedOperationException("It's your job to implement this method"); // todo
+        return String::isEmpty;
     }
 
     /**
@@ -30,7 +31,7 @@ public static Predicate<String> isEmptyPredicate() {
      * @return function that converts adds dollar sign
      */
     public static Function<BigDecimal, String> toDollarStringFunction() {
-        throw new UnsupportedOperationException("It's your job to implement this method"); // todo
+        return bigDecimal -> "$" + bigDecimal;
     }
 
     /**
@@ -42,7 +43,7 @@ public static Function<BigDecimal, String> toDollarStringFunction() {
      * @return a string predicate
      */
     public static Predicate<String> lengthInRangePredicate(int min, int max) {
-        throw new UnsupportedOperationException("It's your job to implement this method"); // todo
+        return str -> str.length() >= min && str.length() < max;
     }
 
     /**
@@ -51,7 +52,7 @@ public static Predicate<String> lengthInRangePredicate(int min, int max) {
      * @return int supplier
      */
     public static IntSupplier randomIntSupplier() {
-        throw new UnsupportedOperationException("It's your job to implement this method"); // todo
+        return () -> ThreadLocalRandom.current().nextInt();
     }
 
 
@@ -61,7 +62,7 @@ public static IntSupplier randomIntSupplier() {
      * @return int operation
      */
     public static IntUnaryOperator boundedRandomIntSupplier() {
-        throw new UnsupportedOperationException("It's your job to implement this method"); // todo
+        return bound -> ThreadLocalRandom.current().nextInt(bound);
     }
 
     /**
@@ -70,7 +71,7 @@ public static IntUnaryOperator boundedRandomIntSupplier() {
      * @return square operation
      */
     public static IntUnaryOperator intSquareOperation() {
-        throw new UnsupportedOperationException("It's your job to implement this method"); // todo
+        return a -> a * a;
     }
 
     /**
@@ -79,7 +80,7 @@ public static IntUnaryOperator intSquareOperation() {
      * @return binary sum operation
      */
     public static LongBinaryOperator longSumOperation() {
-        throw new UnsupportedOperationException("It's your job to implement this method"); // todo
+        return (a, b) -> a + b;
     }
 
     /**
@@ -88,7 +89,7 @@ public static LongBinaryOperator longSumOperation() {
      * @return string to int converter
      */
     public static ToIntFunction<String> stringToIntConverter() {
-        throw new UnsupportedOperationException("It's your job to implement this method"); // todo
+        return Integer::parseInt;
     }
 
     /**
@@ -99,9 +100,10 @@ public static ToIntFunction<String> stringToIntConverter() {
      * @return a function supplier
      */
     public static Supplier<IntUnaryOperator> nMultiplyFunctionSupplier(int n) {
-        throw new UnsupportedOperationException("It's your job to implement this method"); // todo
+        return () -> a -> n * a;
     }
 
 
 }
 
+