If you have any questions about using the if statement in JavaScript, please comment below. Finally, if our first two conditions are proved false, we utilize the JavaScript else conditional statement to print out the message The Day isn't Wednesday or Friday. Using the else statement you can run a code block only if the previous conditional statements were false. We start our example script by instantiating the date object and storing it in the date variable. As you can see in the screenshot below, the console is completely empty. The if statement has the console.log() function inside it used to write a message on the console. In this script, we will get the current day of the week and use a conditional statement to see if it is Wednesday. To open up the browser console: In the example above, we first declared a variable named number and then assigned it a value of 2. Sometimes you will want to run an if statement in JavaScript only if the first one was true. The ifelse statement allows you to execute one block of code if the specified condition is evaluates to true and another block of code if it is evaluates to false. For example, it allows you to write dynamic code that reacts to elements on a page or user input. Leaves are falling!'. A value is considered truthy whenever its value is not false, undefined, null, 0, -0, NAN, or an empty string (""). The else-if statement is used to specify a new condition that runs if the original statement is false. Use the optional else clause to execute another group of statements. Its basic syntax is: If the condition is evaluated to true the value1 will be returned, otherwise value2 will be returned. The else statement only runs in case the original condition is false. By adding an else statement to the end of an if statement we can print a message stating that it is not Wednesday. Let us build upon the example we used in the if statement section. if the current day is Friday, otherwise it will output the text "Have a nice day!". B. When the first condition is false, we then utilize the JavaScript else if statement to test whether the day is identical to 5 (Friday). You will find this statement useful when you only want code to be run when a condition isnt met. Write a conditional statement to make this happen! With the example below, we first use an if statement to check if the day of the week is identical to 3. With the if conditional statement, we check that the current day is identical to 3. on some conditions. Lets take a look at the syntax: The else if statements allow you to have multiple possible outcomes. Below is an example of what nested conditional statements look like when written in JavaScript. Add a final else if statement that checks if season is equal to 'summer'. Like many other programming languages, JavaScript also allows you to write code that perform different actions based on the results of a logical or comparative test conditions at run time. You nest an if statement by using one within another if statement. If the day variables value is identical to 3, the message The Day is Wednesday will be logged. Add another else if statement that checks if season is equal to 'fall'. statements_1, statements_2 : Can be any JavaScript statements, including further nested if statements. So the editor moves on to the else-if condition. Use the F12 key in Chrome and other chromium-based browsers. Is this website helpful to you? }, At least 1 uppercase letter and 1 lowercase letter. What this shows us is a combination of all the if statements that are supported within JavaScript. } else { The following example will output "Have a nice weekend!" A conditional statement is a set of commands and the commands execute if a specified condition is true. or share your feedback to help us improve. These are a crucial part of JavaScript as it allows you to perform different actions when a condition has been met. The first if statement we use in our JavaScript example will check whether the day is identical to the number 3 (Wednesday). Make sure your password is at least 8 characters and contains: Avoid common passwords or strings like password, qwerty, or 12345. This behavior is achieved by using what is called nested if statements. } else if (stopLight === 'green') { As 11 is greater than 10, the original condition of the if statement was false, and the body of the else statement was executed. Your email address will not be published. We then have our first if statement, which we used to check if the day is identical (===) to number 3 (Wednesday). This work is licensed under a Creative Commons Attribution 4.0 International License. Notify me of follow-up comments by email. Receive our Raspberry Pi projects, coding tutorials, Linux guides and more! console.log('Go! if the current day is Sunday, otherwise it will output "Have a nice day!". Lets create a program that keeps track of the way the environment changes with the seasons. If you need to check specifically for an empty string over null, I would think checking against "" is your best bet, using the === operator (so that you know that it is, in fact, a string you're comparing against). Finally, we use our JavasScripts if statement to check whether the day variable is identical (===) to 3 (Wednesday). like, The next conditional statement we will explore is the JavaScript ifelse statement. console.log('Caution, unknown! In this condition, we check if the day is identical to 5. Copyright 2022 Tutorial Republic. In the example given above, the number is equal to 10. '); if the current day is Friday, and "Have a nice Sunday!" Please give us a If you just want to check whether there's any value, you can do. The final JavaScript conditional statement that we will be looking into is the if else if else statement. Inside the code block of the else if statement, add a console.log() that prints the string 'It\'s winter! If this condition is met, we print the text It is after midday.

In the example above, since stopLight === 'red' evaluates to false and stopLight === 'yellow' evaluates to true, the code inside the first else if statement is executed.

For this example, we will be retrieving the current day by using the Date() object. See the Pen javascript-common-editor by w3resource (@w3resource) on CodePen. It is most commonly used on the client-side to add interactivity to a static webpage. '); Then we used a conditional statement to verify whether the number is less than 10. We will take the above-mentioned program as an example once again: In the above-given example, we added another statement, i.e., else. The ternary operator provides a shorthand way of writing the ifelse statements. if the current day is Friday: You can enhance the decision making capabilities of your JavaScript program by providing an alternative choice through adding an else statement to the if statement. It can be written, like this: The JavaScript code in the following example will output "Have a nice weekend!" Next: JavaScript: Switch statement. This means, you can create test conditions in the form of expressions that evaluates to either true or false and based on these results you can perform certain actions. Finally, if none of the previous conditions are met, you can use the else statement to run additional code. In this tutorial, we will be showing you how to write the if, else, and else if conditional statements in JavaScript. In this write-up, we discussed what is an if statement. If none of the conditions evaluated to true, then the code in the else statement would have executed. The JavaScript if statement allows you to run a code block when the condition you specify is true. For example, 1 === 1 is a statement that is truthy, whereas 1 === 2 is a statement that is falsy. If the day isnt set to 3, we utilize JavaScripts else if statement to check if a different condition is met. Your email address will not be published. Over the next few sections, we will touch on the the following conditional statements in JavaScript: if, ifelse, ifelse if, ifelse ifelse. Let us write a short script to show you how the if statement works within JavaScript. The else if statement allows for more than two possible outcomes. HTML-CSS Practical: Exercises, Practice, Solution, Java Regular Expression: Exercises, Practice, Solution, Scala Programming Exercises, Practice, Solution. See the following syntax: Previous: JavaScript: Block statement These statements perform different actions under different conditions; if the defined/specified criteria are met, the block of code in the body of the if statement will be executed. Below you can see the general syntax for using the if statement within JavaScript. I have experience working with Vue, React & Node.js & currently working on article writing and video creation. condition_1, condition_2 : Can be any JavaScript expression that evaluates to true or false. You start by checking if a particular condition is met. The if statements are conditional statements that make decisions based on the defined criteria. Start the script by instantiating the Date() object and assigning it to a constant named date. To understand how this operator works, consider the following examples: Using the ternary operator the same code could be written in a more compact way: As you can see in the above example, since the specified condition evaluated to false the value on the right side of the colon (:) is returned, which is the string 'Adult'. If we change the value of the number variable from 2 to 11, then the condition will become false, and the body of the if statement will not be executed. console.log('Slow down. The else if statement always comes after the if statement and before the else statement. We then access the date objects getDay() function to get the day of the week and store it in a variable called day. If that condition hasnt been met, you can check if another condition is met. Linux Hint LLC, [emailprotected] The ifelse ifelse a special statement that is used to combine multiple ifelse statements. With this condition, we check if the hour variable is greater than 12. There are two conditional statements in JavaScript : ifelse and switch. In this tutorial you will learn how to write the decision-making code using ifelseelse if conditional statements in JavaScript. For multiple conditions, we can use else if. In main.js there is already an ifelse statement in place. if (stopLight === 'red') { However, it provides a great way to write compact if-else statements. Lets add an else if statement that checks if season is equal to 'winter'. In this way, we can have multiple conditions that will only run if the original condition is false. In JavaScript, a conditional statement allows you to perform an action when a particular condition is considered truthy. Throughout this guide, we have shown you how to use if, else, and else if conditional statements in JavaScript. Finally, we have our JavaScripts nested if statement. Let us start this guide off with the most basic conditional statement that you should learn, the if statement. If the day variable is identical to 5, we print the message The Day is Friday. We have covered how JavaScript handles whether a condition is considered truthy or falsy. 1309 S Mary Ave Suite 210, Sunnyvale, CA 94087 The ternary operator is represented by the question mark (?) We can add more conditions to our ifelse with an else if statement. Dont get confused between a Boolean true and false and truthy and falsy. So the original condition is false. JavaScript is a text-based scripting/programming language used in front and back-end development. If the above condition is met, we print the text The Day is Wednesday to the console. For this example, we will retrieve the date using the Date object and print text based on what day it is. How can I check for an empty/undefined/null string in JavaScript? if/else if/else statements are read from top to bottom, so the first condition that evaluates to true from the top to bottom is the block that gets executed. We then use the date object again to get the current hour of the day using the .getHours() function and store it in the hour variable. If the day is identical to 3, then the text The Day is Wednesday will be printed to the console. '); Parentheses are required around the condition. Below is an example of how you would write an if, else if, else conditional statement within JavaScript. } else if (stopLight === 'yellow') { You can add as many else if statements as youd like, to make more complex conditionals! You can achieve this by using the else if conditional statement in JavaScript This statement allows you to check if a condition is true if the first is false. The else if statement also takes a condition. Below you can see the syntax for using the if else statement within JavaScript. Switch statements can be used as an alternative to if-else statements, but they can only check for equality, while the if-else statements can have a range of values as a condition. Inside the code block of the else if statement you just created, add a console.log() that prints the string 'It\'s fall! Immediately afterward, we get the current day of the week using the .getDay() function and store its value in the day variable. The else statement must always be used at the end of an if else if statement chain. In some cases, you may want to check if another condition is met when your first condition proves to be false. The rest of the conditions are not evaluated. You will learn about the JavaScript switch-case statement in the next chapter. The editor does not check the else statement as one of the conditions is already true. See the following syntax : Here the if else if.. statement checks the grade of Math. It is a good practice to use a block statement ( {.}) to execute multiple statements. There are several conditional statements in JavaScript that you can use to make decisions: We will discuss each of these statements in detail in the coming sections. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Disclaimer & Privacy Policy | About us | Contact, Running x86 Software on a Raspberry Pi using Box86, Raspberry Pi Accelerometer using the ADXL345, How to Setup WordPress on the Raspberry Pi, The Ultimate Guide to the Raspi-Config Tool. Required fields are marked *. Privacy Policy and Terms of Use. We can combine the if statement with an else statements as well. The if statements can be used in different forms depending upon the complexity of the condition. Executes a group of statements if a logical condition is true. symbol and it takes three operands: a condition to check, a result for true, and a result for false.

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Inside the code block of the else if statement you just created, add a console.log() that prints the string 'It\'s sunny and warm because it\'s summer!'. Note: We will use the browser console to demonstrate examples performed in this post. Backbone.js Model.PreviousAttributes() Method. Connect with us on Facebook and Twitter for the latest updates. Once a condition is matched/true, the other else-if statements are not checked by the editor/compiler. A Javascript Developer & Linux enthusiast with 4 years of industrial experience and proven know-how to combine creative and usability viewpoints resulting in world-class web applications. As the number is equal to 10, this statement is true, and the body of the else-if statement is executed. Putting one if statement inside another if statement is called nesting. As 2 < 10, the condition of the if statement was true, and the body was executed. Be sure to check our other JavaScript tutorials and many other coding guides. Test your Programming skills with w3resource's quiz. Everything is covered in snow.'. The if statement is used to execute a block of code only if the specified condition evaluates to true. Tip: Code written using the ternary operator can be difficult to read sometimes. Setting up a Raspberry Pi Scanner Server using SANE, Example of Writing an if Statement in JavaScript, Example of Using The if else Conditional Statement, Using the ifelse if Conditional Statement in JavaScript, Example of using the if else if Statement, The JavaScript ifelse ifelse Conditional Statement, Example of Writing the if, else if, else Conditional Statement. This is the simplest JavaScript's conditional statements and can be written like: The following example will output "Have a nice weekend!" In computing, if a decision-making/conditional statement is used to run a block of code if a particular condition is satisfied. In the following example if else statement check whether an input marks is greater than 50 or not.

The specified condition needs to be truthy for a statement to be run. console.log('Stop! Using these conditional statements, you can write code that performs an action when the specified condition is met. The syntax below shows you how you can write an if else if conditional statement within JavaScript. let stopLight = 'yellow'; If the condition evaluates to true, the statements in statement_1 are executed, otherwise, statement_2 is executed. If the day is identical to 5 we will print text The Day is Friday to the console. If the statement is true, we log the text The Day is Wednesday. If it isnt identical, the code will fall through to our else statement and print the text The Day is not Wednesday. All Rights Reserved. Moreover, we also learned to use it and combine it with else and else if to check for more complex conditions. This is useful when you want to run some code, then perform some additional actions if another condition is true.
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