SDET Interview QA

Question 1: Given an array of integers, write a Java function to find the two numbers that add up to a given target sum.

Answer:

public int[] findTwoSum(int[] nums, int target) 
    HashMap<Integer, Integer> map = new HashMap<>();
    for (int i = 0; i < nums.length; i++) {
        int complement = target - nums[i];
        if (map.containsKey(complement)) {
            return new int[]{map.get(complement), i};
        }
        map.put(nums[i], i);
    }
    return new int[]{-1, -1}; // If no two numbers add up to the target
}

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Question 2: Implement a Java method to find the intersection of two arrays.

Answer:

public int[] findIntersection(int[] arr1, int[] arr2) 
    HashSet<Integer> set1 = new HashSet<>();
    for (int num : arr1) {
        set1.add(num);
    }


    HashSet<Integer> intersection = new HashSet<>();
    for (int num : arr2) {
        if (set1.contains(num)) {
            intersection.add(num);
        }
    }


    int[] result = new int[intersection.size()];
    int i = 0;
    for (int num : intersection) {
        result[i++] = num;
    }


    return result;
}

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Question 3: Write a Java function to determine if a given string is an anagram of another string.

Answer:

public boolean isAnagram(String str1, String str2) 
    if (str1.length() != str2.length()) {
        return false;
    }


    char[] charArray1 = str1.toCharArray();
    char[] charArray2 = str2.toCharArray();


    Arrays.sort(charArray1);
    Arrays.sort(charArray2);


    return Arrays.equals(charArray1, charArray2);
}

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Question 4: Implement a Java method to check if a given number is a prime number.

Answer:

public boolean isPrime(int num) 
    if (num <= 1) {
        return false;
    }
    for (int i = 2; i <= Math.sqrt(num); i++) {
        if (num % i == 0) {
            return false;
        }
    }
    return true;
}

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Question 5: Write a Java function to reverse a linked list.

Answer:

public ListNode reverseLinkedList(ListNode head) 
    ListNode prev = null;
    ListNode curr = head;
    ListNode next;


    while (curr != null) {
        next = curr.next;
        curr.next = prev;
        prev = curr;
        curr = next;
    }


    return prev;
}

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Question 6: Write a Java code snippet to send a GET request using RestAssured and validate the response status code.

Answer:

import static io.restassured.RestAssured.*


public class RestAssuredExample {
    public static void main(String[] args) {
        // Send GET request and validate response status code
        given()
            .when()
                .get("https://api.example.com/users")
            .then()
                .assertThat()
                .statusCode(200);
    }
}

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Question 7: Implement a Java method using RestAssured to send a POST request with a JSON payload and validate the response body.

Answer:

import io.restassured.http.ContentType


import static io.restassured.RestAssured.*;


public class RestAssuredExample {
    public static void main(String[] args) {
        // Prepare JSON payload
        String jsonPayload = "{\"name\": \"John Doe\", \"email\": \"john.doe@example.com\"}";


        // Send POST request with JSON payload and validate response body
        given()
            .contentType(ContentType.JSON)
            .body(jsonPayload)
        .when()
            .post("https://api.example.com/users")
        .then()
            .assertThat()
            .statusCode(201)
            .body("name", equalTo("John Doe"))
            .body("email", equalTo("john.doe@example.com"));
    }
}

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Question 8: Write a Java method using RestAssured to extract and validate a specific value from a JSON response.

Answer:

import static io.restassured.RestAssured.*
import static org.hamcrest.Matchers.*;


public class RestAssuredExample {
    public static void main(String[] args) {
        // Send GET request and validate a specific value from the JSON response
        given()
            .when()
                .get("https://api.example.com/users/123")
            .then()
                .assertThat()
                .statusCode(200)
                .body("name", equalTo("John Doe"))
                .body("age", greaterThan(18));
    }
}

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Question 9: Implement a Java method using RestAssured to send a DELETE request and validate the absence of a resource.

Answer:

import static io.restassured.RestAssured.*
import static org.hamcrest.Matchers.*;


public class RestAssuredExample {
    public static void main(String[] args) {
        // Send GET request and validate response headers
        given()
            .when()
                .get("https://api.example.com/users")
            .then()
                .assertThat()
                .statusCode(200)
                .header("Content-Type", containsString("application/json"))
                .header("Cache-Control", equalTo("max-age=3600"));
    }
}

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Question 10: Write a Java method using RestAssured to extract and validate the response headers.

Answer:

import static io.restassured.RestAssured.*
import static org.hamcrest.Matchers.*;


public class RestAssuredExample {
    public static void main(String[] args) {
        // Send GET request and validate response headers
        given()
            .when()
                .get("https://api.example.com/users")
            .then()
                .assertThat()
                .statusCode(200)
                .header("Content-Type", containsString("application/json"))
                .header("Cache-Control", equalTo("max-age=3600"));
    }
}

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