JavaScript Statements
Statements are the building blocks of every JavaScript program — the keywords that make decisions, repeat work and structure your code. From if...else and for loops to function, class and async/await, here are all 24, each with its syntax and live, editable examples.
| Name | Description |
|---|---|
| async function | Declares a function that returns a promise and can use await for asynchronous code. |
| await | Pauses an async function until a promise settles, then resumes with its resolved value. |
| break | Immediately exits the nearest loop or switch statement. |
| class | Defines a blueprint for creating objects, with a constructor, methods and inheritance. |
| const | Declares a block-scoped constant that cannot be reassigned. The recommended default. |
| continue | Skips the rest of the current loop iteration and moves to the next one. |
| do...while | A loop that runs its body first and then checks the condition, so it always runs at least once. |
| export | Makes values from a module available for other files to import. |
| for | Repeats a block of code a set number of times using a counter you control. |
| for...in | Loops over the enumerable keys of an object. Not recommended for arrays. |
| for...of | Loops over the values of an iterable such as an array, string, Map or Set. |
| function | Declares a reusable block of code that can take inputs and return a value. |
| function* | A function that can pause and resume, producing a sequence of values one at a time. |
| if...else | Runs a block of code when a condition is true, with optional else and else if branches. |
| import | Brings exported values from another module into the current file. |
| let | Declares a block-scoped variable that can be reassigned. The default choice with const. |
| return | Ends a function and sends a value back to the code that called it. |
| switch | Compares a value against several cases and runs the matching block. Don't forget break. |
| this | A keyword whose value is the object a function is called on — it depends on how the function is invoked. |
| throw | Raises an error, stopping normal execution and jumping to the nearest catch block. |
| try...catch | Runs code that might fail and catches any error so the program can recover gracefully. |
| var | The old way to declare a variable. Function-scoped and hoisted — prefer let and const. |
| while | Repeats a block of code as long as a condition stays true. |
| yield | Pauses a generator function and produces a value to the caller. Resumes on the next request. |