A when statement considers one or more conditions and returns a value as soon as that condition is met.

Weekly challenge 4

LATEST SUBMISSION GRADE 100%

Question 1

The data collected for an analysis project has just been cleaned. What are the next steps for a data analyst? Select all that apply.

• Reporting
• Certification
• Verification
• Validation

Correct. Verification and reporting are the next steps for a data analyst after the data is cleaned.

Question 2

What is involved in seeing the big picture when verifying data cleaning? Select all that apply.

• Consider the data.
• Consider the reporting.
• Consider the goal.
• Consider the business problem.

Correct. To see the big picture when verifying data cleaning, consider the business problem, the goal, and the data.

Question 3

Which of the following functions automatically remove extra spaces when cleaning data?

• TRIM
• CLEAR
• REMOVE
• SNIP

Correct. TRIM automatically removes extra spaces when cleaning data.

Question 4

What tool can a data analyst use to figure out how many identical errors occur in a dataset?

• CONFIRM
• COUNT
• COUNTA
• CASE

Correct. A data analyst can use COUNTA to figure out how many identical errors occur in a dataset.

Question 5

A WHEN statement considers one or more conditions and returns a value as soon as that condition is met.

• True
• False

Correct. A CASE statement considers one or more conditions and returns a value as soon as that condition is met.

Question 6

What is the process of tracking changes, additions, deletions, and errors during data cleaning?

• Observation
• Cataloging
• Documentation
• Recording

Correct. Documentation is the process of tracking changes, additions, deletions, and errors during data cleaning.

Question 7

At what point during the analysis process does a data analyst use a changelog?

• While reporting the data
• While gathering the data
• While cleaning the data
• While visualizing the data

Correct. A data analyst uses a changelog while cleaning data.

Question 8

A data analyst commits a query to the repository as a new and improved query. Then, they specify the changes they made and why they made them. This scenario is part of what process?

• Visualizing data
• Creating a changelog
• Reporting data
• Communicating with stakeholders

Correct. Specifying the changes an analyst made and why they made them is part of creating a changelog.

EXTRA QUESTIONS

Question

What is the first step in the verification process?

• Inform others of your data-cleaning effort.
• Create a chronological list of modifications made to the data.
• Determine the quality of the data.
• Compare cleaned data with the original, uncleaned dataset and compare it to what is there now.

Correct. The first step in the verification process is to compare cleaned data with the original, uncleaned dataset and compare it to what is there now.

Question

Fill in the blank: A changelog contains a _____ list of modifications made to a project.

• chronological
• synchronized
• approximate
• random

Correct. A data analyst uses a changelog to access the information needed. A changelog is a file that contains a chronological list of modifications made to a project.

🗂️ Page Index for this GitHub Wiki

The if-else or conditional statement will perform some action for a specific condition. If the condition meets then a particular block of action will be executed otherwise it will execute another block of action that satisfies that particular condition. Such control statements are used to cause the flow of execution to advance and branch based on changes to the state of a program.

Example: This example describes the if-statement in Javascript.

Javascript

<script type = "text/javaScript">

    var i = 10;

    if (i > 15) document.write("10 is less than 15");

    console.log("I am Not in if");

</script>

Output:

I am Not in if

JavaScript’s conditional statements:

• if
• if-else
• nested-if
• if-else-if ladder

We will understand each conditional statement, its syntax, flowchart, and examples. Please refer to the Switch Case in JavaScript article to understand the switch case. Let’s begin with the if-statement.

if-statement: It is a conditional statement used to decide whether a certain statement or block of statements will be executed or not i.e if a certain condition is true then a block of statement is executed otherwise not.

Syntax:

if(condition) { // Statements to execute if // condition is true }

The if statement accepts boolean values – if the value is true then it will execute the block of statements under it. If we do not provide the curly braces ‘{‘ and ‘}’ after if( condition ) then by default if statement considers the immediate one statement to be inside its block. For example,

if(condition) statement1; statement2; // Here if the condition is true, if block // will consider only statement1 to be inside // its block.

Flow chart:

if-condition statement

if-else statement: The if statement alone tells us that if a condition is true it will execute a block of statements and if the condition is false it won’t. But what if we want to do something else if the condition is false? Here comes the else statement. We can use the else statement with the if statement to execute a block of code when the condition is false.

Syntax:

if (condition) { // Executes this block if // condition is true } else { // Executes this block if // condition is false }

Flow chart:

if-else statement

Example: This example describes the if-else statement in Javascript.

JavaScript

<script type="text/javaScript">

    var i = 10;

    if (i < 15)

     console.log("i is less than 15");

    else

     console.log("I am Not in if");

</script>

Output:

i is smaller than 15

nested-if statement: JavaScript allows us to nest if statements within if statements. i.e, we can place an if statement inside another if statement. A nested if is an if statement that is the target of another if or else. 

Syntax:

if (condition1) { // Executes when condition1 is true if (condition2) { // Executes when condition2 is true } }

Flow chart:

nested-if statement

Example: This example describes the nested-if statement in Javascript.

JavaScript

<script type = "text/javaScript">

    var i = 10;

    if (i == 10) {

      if (i < 15)

        console.log("i is smaller than 15");

      if (i < 12)

        console.log("i is smaller than 12 too");

      else

        console.log("i is greater than 15");

    }

</script>

Output:

i is smaller than 15 i is smaller than 12 too

if-else-if ladder statement: Here, a user can decide among multiple options.The if statements are executed from the top down. As soon as one of the conditions controlling the if is true, the statement associated with that if is executed, and the rest of the ladder is bypassed. If none of the conditions is true, then the final else statement will be executed.

Syntax:

if (condition) statement; else if (condition) statement; . . else statement;

Flow chart:

if-else-if ladder statement

Example: This example describes the if-else-if ladder statement in Javascript.

JavaScript

<script type = "text/javaScript">

    var i = 20;

    if (i == 10)

      console.log("i is 10");

    else if (i == 15)

      console.log("i is 15");

    else if (i == 20)

      console.log("i is 20");

    else

      console.log("i is not present");

</script>

Output:

i is 20

Supported Browsers:

• Google Chrome 1.0
• Firefox 1.0
• Microsoft Edge 12.0
• Internet Explorer 3.0
• Opera 3.0
• Safari 1.0

Which SQL tool considers one or more conditions then returns a value as soon as a condition is met?

What do you need to consider when you make a table in SQL?

How do you write if else condition in SQL query?

How does case work in SQL?