You asked: What is block statement in JavaScript?

What is a block statement?

A block statement is a sequence of zero or more statements enclosed in braces. … In some situations, you can use only one statement. If you want to use more than one statement in those situations, you can create a block statement by placing all your statements inside braces, which would be treated as a single statement.

How do you block in JavaScript?


  1. Click the padlock “site info” icon on the left side of the URL bar, then click “Site Settings.”
  2. Scroll down until you find the “JavaScript” option, then select “Block” from the drop-down menu to the right. Repeat as necessary for every site where you want to block JavaScript.

What is var let and Const in JavaScript?

There are 3 ways to declare variables in JavaScript: using const , let , or var statements. Specific to const variable is that you have to initialize the variable with an initial value. Also, the const variable cannot be reassigned. let , on the other side, can be declared with or without an initial value.

What is a JavaScript statement?

Statements are used in JavaScript to control its program flow. Unlike properties, methods, and events, which are fundamentally tied to the object that owns them, statements are designed to work independently of any JavaScript object.

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What is a block give an example?

The definition of a block is a square piece of material that usually has flat surfaces that may be used for building things, as a child’s toy, or as a work surface. An example of a block is a large piece of wood that is square in shape.

What is the difference between a statement and a block?

Your definitions are correct.

If is actually both typically. The if statement itself is just that, a control flow statement. If the statement is evaluated to true it executes the statement, or block after it. In other words, the block after an if is not required if you just wanted to execute a single line of code.

What happens if I turn off JavaScript?

Disabling JavaScript may break the ability to log in, post comments, or dynamically request content, which has become incredibly common on the web today. … You don’t have to wait for a new web page to load—it all happens on the current web page without any obnoxious load times.

What is the main purpose of using blocks?

A block creates a const copy of any local variable that is referenced inside of its scope. Before blocks, whenever you wanted to call some code and have it call you back later, you would typically use delegates or NSNotificationCenter.

Where do I find JavaScript in settings?

Activate JavaScript in Google Chrome

  1. Open Chrome on your computer.
  2. Click. Settings.
  3. Click Privacy and security.
  4. Click Site settings.
  5. Click JavaScript.
  6. Turn on Allowed (recommended).

Is Let hoisted?

Let and const hoisting

Variables declared with let and const are also hoisted, but unlike for var the variables are not initialized with a default value of undefined . Until the line in which they are initialized is executed, any code that accesses these variables will throw an exception.

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Should I use VAR or let?

The main difference between the two though is that let deals with block scope whereas var deals with global scope or function scope depending on where it’s declared. As long as your variable isn’t declared within any function, var can be used again anywhere else in your code.

Why do we use const?

We use the const qualifier to declare a variable as constant. That means that we cannot change the value once the variable has been initialized. … For example, if you have a constant value of the value of PI, you wouldn’t like any part of the program to modify that value. So you should declare that as a const.