Practice 70 Java Lambda Expression Programming Questions

Practice 70 Java Lambda Expression Programming Questions

Q1. Write a Java program to implement a lambda expression that adds two numbers.  
Input:  
a = 5, b = 10  
Expected Output:  
Sum = 15  

Q2. Write a Java program to implement a lambda expression that checks if a number is even.  
Input:  
num = 8  
Expected Output:  
true  

Q3. Write a Java program to implement a lambda expression that multiplies two numbers.  
Input:  
a = 3, b = 4  
Expected Output:  
Product = 12  

Q4. Write a Java program to implement a lambda expression that finds the maximum of two numbers.  
Input:  
a = 10, b = 15  
Expected Output:  
Max = 15  

Q5. Write a Java program to implement a lambda expression that checks if a string is empty.  
Input:  
str = "Hello"  
Expected Output:  
false  

Q6. Write a Java program to implement a lambda expression that returns the length of a string.  
Input:  
str = "Lambda"  
Expected Output:  
Length = 6  

Q7. Write a Java program to implement a lambda expression that converts a string to uppercase.  
Input:  
str = "java"  
Expected Output:  
JAVA  

Q8. Write a Java program to implement a lambda expression that checks if a number is positive.  
Input:  
num = 7  
Expected Output:  
true  

Q9. Write a Java program to implement a lambda expression that returns the square of a number.  
Input:  
num = 4  
Expected Output:  
16  

Q10. Write a Java program to implement a lambda expression that calculates the factorial of a number.  
Input:  
num = 5  
Expected Output:  
120  

Q11. Write a Java program to implement a lambda expression that calculates the sum of an array of integers.  
Input:  
arr = [1, 2, 3, 4]  
Expected Output:  
Sum = 10  

Q12. Write a Java program to implement a lambda expression that checks if a number is divisible by 5.  
Input:  
num = 20  
Expected Output:  
true  

Q13. Write a Java program to implement a lambda expression that returns the product of all elements in an array.  
Input:  
arr = [2, 3, 4]  
Expected Output:  
Product = 24  

Q14. Write a Java program to implement a lambda expression that reverses a string.  
Input:  
str = "Lambda"  
Expected Output:  
adbmaL  

Q15. Write a Java program to implement a lambda expression that finds the smallest number in an array.  
Input:  
arr = [5, 3, 8, 1]  
Expected Output:  
Smallest = 1  

Q16. Write a Java program to implement a lambda expression that returns the cube of a number.  
Input:  
num = 3  
Expected Output:  
27  

Q17. Write a Java program to implement a lambda expression that concatenates two strings.  
Input:  
str1 = "Hello", str2 = "World"  
Expected Output:  
HelloWorld  

Q18. Write a Java program to implement a lambda expression that returns the absolute value of a number.  
Input:  
num = -10  
Expected Output:  
10  

Q19. Write a Java program to implement a lambda expression that calculates the area of a circle (πr²).  
Input:  
radius = 7  
Expected Output:  
Area = 153.93804002589985  

Q20. Write a Java program to implement a lambda expression that checks if a string contains a given substring.  
Input:  
str = "Lambda", substring = "am"  
Expected Output:  
true  

Q21. Write a Java program to implement a lambda expression that finds the factorial of a number using recursion.  
Input:  
num = 4  
Expected Output:  
24  

Q22. Write a Java program to implement a lambda expression that prints the first 10 even numbers.  
Input:  
No input required  
Expected Output:  
0, 2, 4, 6, 8, 10, 12, 14, 16, 18  

Q23. Write a Java program to implement a lambda expression that checks if a number is a palindrome.  
Input:  
num = 121  
Expected Output:  
true  

Q24. Write a Java program to implement a lambda expression that returns the greater of two numbers.  
Input:  
a = 6, b = 9  
Expected Output:  
9  

Q25. Write a Java program to implement a lambda expression that returns the even-indexed elements of an array.  
Input:  
arr = [1, 2, 3, 4, 5]  
Expected Output:  
1, 3, 5  

Q26. Write a Java program to implement a lambda expression that converts a string to lowercase.  
Input:  
str = "JAVA"  
Expected Output:  
java  

Q27. Write a Java program to implement a lambda expression that checks if a number is divisible by 3.  
Input:  
num = 9  
Expected Output:  
true  

Q28. Write a Java program to implement a lambda expression that returns the length of the longest string in an array.  
Input:  
arr = ["apple", "banana", "cherry"]  
Expected Output:  
Length = 6  

Q29. Write a Java program to implement a lambda expression that returns the second largest number in an array.  
Input:  
arr = [2, 4, 1, 6, 8]  
Expected Output:  
6  

Q30. Write a Java program to implement a lambda expression that converts a string to a number.  
Input:  
str = "123"  
Expected Output:  
123  

Q31. Write a Java program to implement a lambda expression that checks if a string starts with a given prefix.  
Input:  
str = "Lambda", prefix = "La"  
Expected Output:  
true  

Q32. Write a Java program to implement a lambda expression that sorts an array of integers in ascending order.  
Input:  
arr = [3, 1, 4, 5, 2]  
Expected Output:  
1, 2, 3, 4, 5  

Q33. Write a Java program to implement a lambda expression that filters out even numbers from a list.  
Input:  
List = [1, 2, 3, 4, 5]  
Expected Output:  
1, 3, 5  

Q34. Write a Java program to implement a lambda expression that doubles each number in a list.  
Input:  
List = [1, 2, 3, 4]  
Expected Output:  
2, 4, 6, 8  

Q35. Write a Java program to implement a lambda expression that finds the square root of a number.  
Input:  
num = 16  
Expected Output:  
4  

Q36. Write a Java program to implement a lambda expression that finds the sum of a list of integers.  
Input:  
List = [1, 2, 3, 4]  
Expected Output:  
10  

Q37. Write a Java program to implement a lambda expression that returns the difference between two numbers.  
Input:  
a = 10, b = 5  
Expected Output:  
5  

Q38. Write a Java program to implement a lambda expression that checks if a string is a palindrome.  
Input:  
str = "madam"  
Expected Output:  
true  

Q39. Write a Java program to implement a lambda expression that finds the average of a list of integers.  
Input:  
List = [5, 10, 15, 20]  
Expected Output:  
12.5  

Q40. Write a Java program to implement a lambda expression that prints each element of a list.  
Input:  
List = [1, 2, 3, 4]  
Expected Output:  
1, 2, 3, 4  

Q41. Write a Java program to implement a lambda expression that filters out odd numbers from a list.  
Input:  
List = [1, 2, 3, 4, 5]  
Expected Output:  
2, 4  

Q42. Write a Java program to implement a lambda expression that returns a string in reverse order.  
Input:  
str = "Functional"  
Expected Output:  
lanotcnuF  

Q43. Write a Java program to implement a lambda expression that checks if a number is a prime number.  
Input:  
num = 11  
Expected Output:  
true  

Q44. Write a Java program to implement a lambda expression that checks if a string contains only digits.  
Input:  
str = "12345"  
Expected Output:  
true  

Q45. Write a Java program to implement a lambda expression that calculates the sum of digits of a number.  
Input:  
num = 1234  
Expected Output:  
10  

Q46. Write a Java program to implement a lambda expression that replaces spaces in a string with dashes.  
Input:  
str = "Java Lambda Expression"  
Expected Output:  
Java-Lambda-Expression  

Q47. Write a Java program to implement a lambda expression that returns the reverse of an array of integers.  
Input:  
arr = [1, 2, 3, 4]  
Expected Output:  
4, 3, 2, 1  

Q48. Write a Java program to implement a lambda expression that converts a list of strings to uppercase.  
Input:  
List = ["hello", "world"]  
Expected Output:  
HELLO, WORLD  

Q49. Write a Java program to implement a lambda expression that filters out strings with length greater than 3.  
Input:  
List = ["one", "two", "three", "four"]  
Expected Output:  
three, four  

Q50. Write a Java program to implement a lambda expression that joins a list of strings into a single string.  
Input:  
List = ["Java", "Lambda", "Expression"]  
Expected Output:  
JavaLambdaExpression  

Q51. Write a Java program to implement a lambda expression that sorts a list of strings alphabetically.  
Input:  
List = ["banana", "apple", "cherry"]  
Expected Output:  
apple, banana, cherry  

Q52. Write a Java program to implement a lambda expression that finds the square of all elements in a list.  
Input:  
List = [2, 3, 4]  
Expected Output:  
4, 9, 16  

Q53. Write a Java program to implement a lambda expression that filters out strings containing the letter 'a'.  
Input:  
List = ["apple", "banana", "cherry", "date"]  
Expected Output:  
banana, date  

Q54. Write a Java program to implement a lambda expression that returns the index of a string in a list.  
Input:  
List = ["java", "python", "javascript"], str = "python"  
Expected Output:  
1  

Q55. Write a Java program to implement a lambda expression that finds the length of the shortest string in a list.  
Input:  
List = ["apple", "banana", "cherry"]  
Expected Output:  
5  

Q56. Write a Java program to implement a lambda expression that removes duplicate numbers from an array.  
Input:  
arr = [1, 2, 2, 3, 4, 4]  
Expected Output:  
1, 2, 3, 4  

Q57. Write a Java program to implement a lambda expression that checks if a number is divisible by both 2 and 3.  
Input:  
num = 6  
Expected Output:  
true  

Q58. Write a Java program to implement a lambda expression that returns the maximum length string from a list.  
Input:  
List = ["apple", "banana", "cherry"]  
Expected Output:  
banana  

Q59. Write a Java program to implement a lambda expression that adds 5 to each number in a list.  
Input:  
List = [1, 2, 3, 4]  
Expected Output:  
6, 7, 8, 9  

Q60. Write a Java program to implement a lambda expression that calculates the sum of all even numbers in a list.  
Input:  
List = [1, 2, 3, 4, 5, 6]  
Expected Output:  
12  

Q61. Write a Java program to implement a lambda expression that checks if a string contains only alphabets.  
Input:  
str = "java"  
Expected Output:  
true  

Q62. Write a Java program to implement a lambda expression that checks if a number is a perfect square.  
Input:  
num = 25  
Expected Output:  
true  

Q63. Write a Java program to implement a lambda expression that finds the sum of odd numbers in an array.  
Input:  
arr = [1, 2, 3, 4, 5]  
Expected Output:  
9  

Q64. Write a Java program to implement a lambda expression that checks if a string is a valid email.  
Input:  
str = "test@example.com"  
Expected Output:  
true  

Q65. Write a Java program to implement a lambda expression that checks if a string contains a vowel.  
Input:  
str = "hello"  
Expected Output:  
true  

Q66. Write a Java program to implement a lambda expression that returns the power of a number.  
Input:  
num = 2, power = 3  
Expected Output:  
8  

Q67. Write a Java program to implement a lambda expression that sums all integers in a list greater than 10.  
Input:  
List = [5, 10, 15, 20]  
Expected Output:  
35  

Q68. Write a Java program to implement a lambda expression that multiplies all elements in an array.  
Input:  
arr = [2, 3, 4]  
Expected Output:  
24  

Q69. Write a Java program to implement a lambda expression that filters out strings shorter than 5 characters.  
Input:  
List = ["java", "lambda", "expression"]  
Expected Output:  
lambda, expression  

Q70. Write a Java program to implement a lambda expression that prints all even numbers from 1 to 20.  
Input:  
No input required  
Expected Output:  
2, 4, 6, 8, 10, 12, 14, 16, 18