Comments let you hide parts of your code from being executed. They are useful when you want to temporarily disable code or leave notes for yourself or other developers.

Note

Comments are ignored by the interpreter and are helpful for documentation.

Single-line Comments (`//`)

Single-line comments ignore everything on the same line.


              123
            
console.log("Line 1");
// console.log("Line 2");
console.log("Line 3");

Only the commented-out line is skipped.

You can also comment multiple consecutive lines:


              12345
            
console.log("Line 1");
console.log("Line 2");
// console.log("Line 3");
// console.log("Line 4");
console.log("Line 5");

Or add a comment at the end of a line:


              123
            
console.log("Part 1.1"); console.log("Part 1.2");
console.log("Part 2.1"); // console.log("Part 2.2")
console.log("Part 3.1"); console.log("Part 3.2");

Multi-line Comments (`/* ... */`)

Use multi-line comments when you want to disable larger sections of code.


              1234567891011
            
console.log("Line 1");
console.log("Line 2");
/*
console.log("Line 4");
console.log("Line 5");
console.log("Line 6");
console.log("Line 7");
console.log("Line 8");
console.log("Line 9");
*/
console.log("Line 11");

Everything between /* and */ is ignored.

Multi-line comments can also hide part of a line:


              123
            
console.log("Part 1", /* "Part 2", */ "Part 3");

/* console.log("Part 4"); */ console.log("Part 5");

Everything was clear?

Thanks for your feedback!

Section 1. Chapter 4

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Ask anything or try one of the suggested questions to begin our chat

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Comments let you hide parts of your code from being executed. They are useful when you want to temporarily disable code or leave notes for yourself or other developers.

Note

Comments are ignored by the interpreter and are helpful for documentation.

Single-line Comments (`//`)

Single-line comments ignore everything on the same line.


              123
            
console.log("Line 1");
// console.log("Line 2");
console.log("Line 3");

Only the commented-out line is skipped.

You can also comment multiple consecutive lines:


              12345
            
console.log("Line 1");
console.log("Line 2");
// console.log("Line 3");
// console.log("Line 4");
console.log("Line 5");

Or add a comment at the end of a line:


              123
            
console.log("Part 1.1"); console.log("Part 1.2");
console.log("Part 2.1"); // console.log("Part 2.2")
console.log("Part 3.1"); console.log("Part 3.2");

Multi-line Comments (`/* ... */`)

Use multi-line comments when you want to disable larger sections of code.


              1234567891011
            
console.log("Line 1");
console.log("Line 2");
/*
console.log("Line 4");
console.log("Line 5");
console.log("Line 6");
console.log("Line 7");
console.log("Line 8");
console.log("Line 9");
*/
console.log("Line 11");

Everything between /* and */ is ignored.

Multi-line comments can also hide part of a line:


              123
            
console.log("Part 1", /* "Part 2", */ "Part 3");

/* console.log("Part 4"); */ console.log("Part 5");

Everything was clear?

Thanks for your feedback!

Section 1. Chapter 4

Using Comments to Document Code

Single-line Comments (`//`)

Multi-line Comments (`/* ... */`)

1. Why are comments used in code?

2. How do we create a single-line comment?

3. What is the syntax for creating a multi-line comment?

4. If you have a large code block and enclose it within `/` and `/`, what happens to the enclosed code?

Using Comments to Document Code

Single-line Comments (`//`)

Multi-line Comments (`/* ... */`)

1. Why are comments used in code?

2. How do we create a single-line comment?

3. What is the syntax for creating a multi-line comment?

4. If you have a large code block and enclose it within `/` and `/`, what happens to the enclosed code?

Using Comments to Document Code

Single-line Comments (//)

Multi-line Comments (/* ... */)

1. Why are comments used in code?

2. How do we create a single-line comment?

3. What is the syntax for creating a multi-line comment?

4. If you have a large code block and enclose it within /* and */, what happens to the enclosed code?

Using Comments to Document Code

Single-line Comments (//)

Multi-line Comments (/* ... */)

1. Why are comments used in code?

2. How do we create a single-line comment?

3. What is the syntax for creating a multi-line comment?

4. If you have a large code block and enclose it within /* and */, what happens to the enclosed code?

Single-line Comments (`//`)

Multi-line Comments (`/* ... */`)

4. If you have a large code block and enclose it within `/` and `/`, what happens to the enclosed code?

Single-line Comments (`//`)

Multi-line Comments (`/* ... */`)

4. If you have a large code block and enclose it within `/` and `/`, what happens to the enclosed code?