Flash cards
Review the key moves
What is the main idea behind Java Comments?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
// ___ is a comment System.out.println("Hello World");Put the learning moves in the order that makes the concept easiest to apply.
Comments can be used to explain Java code, and to make it more readable. It can also be used to prevent execution when testing alternative code.
Single-line Comments
Single-line comments start with two forward slashes ( // ).
Any text between // and the end of the line is ignored by Java (will not be executed).
This example uses a single-line comment before a line of code:
Example
// This is a comment System.out.println("Hello World");This example uses a single-line comment at the end of a line of code:
Example
System.out.println("Hello World"); // This is a commentJava Multi-line Comments
Multi-line comments start with /* and ends with */ .
Any text between /* and */ will be ignored by Java.
This example uses a multi-line comment (a comment block) to explain the code:
Example
/* The code below will print the words Hello World
to the screen, and it is amazing */
System.out.println("Hello World");It's up to you which one you use. Normally, we use // for short comments, and /* */ for longer.