arrowcas.blogg.se - Javascript if statement

In the case of many else if statements, the switch statement might be preferred for readability.Īs an example of multiple else if statements, we can create a grading app that will output a letter grade based on a score out of 100. You can have as many else if statements as necessary. JavaScript will attempt to run all the statements in order, and if none of them are successful, it will default to the else block.

The code block will be ignored in the case of a false result, and the program will skip to the next section.Īn if statement is written with the if keyword, followed by a condition in parentheses, with the code to be executed in between curly brackets. An if statement will evaluate whether a statement is true or false, and only run if the statement returns true.

The most fundamental of the conditional statements is the if statement. In this tutorial, we will go over conditional statements, including the if, else, and else if keywords. You can compare a conditional statement to a “ Choose Your Own Adventure” book, or a flowchart.

Display the booking form for a hotel but not if the hotel is bookedĬonditional statements are part of the logic, decision making, or flow control of a computer program.

Display an alcohol purveyor’s website if the user is over the legal drinking age.

Open a dropdown on a click event, or close a dropdown if it is already open.

Send a form on submit, or display warnings next to missing required fields.

Check the location of a user and display the correct language based on country.

In order to achieve tasks like these we have conditional statements, which are an integral part of all programming languages.Ĭonditional statements execute a specific action based on the results of an outcome of true or false.Ī few examples of JavaScript conditional statements you might see include: In programming, there will be many occasions in which you will want different blocks of code to run depending on user input or other factors.Īs an example, you might want a form to submit if each field is filled out properly, but you might want to prevent that form from submitting if some required fields are missing.