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Java

Eric Chan
Eric Chan
4,254 Points
Posted by Eric Chan
Eric Chan
4,254 Points

Difference between system.out.printf and system.out.println

I know this video is not about System.out, but I have been wondering what the difference between .printf and .println is.

Can someone help me clear the cloud? Thanks

Eric Chan
Eric Chan
4,254 Points
Eric Chan
Eric Chan
4,254 Points

now i get it! thanks guys for your help!

2 Answers

Brendon Butler
Brendon Butler
4,254 Points
Brendon Butler
Brendon Butler
4,254 Points

println is used when you want to create a new line with just simple text or even text containing concatenation. ("Hello " + "World" = "Hello World.")

printf is used when you want to format your string. This will clean up any concatenation. For a simple example -> ("Hello, " + username + "! How are you?") could easily be cleaned up a bit by using ("Hello, %s! How are you?", username). It's up to you really when you want to use this.

I would definitely recommend it if you are using multiple variables. In that case you would use multiple conversions in your string. Please feel free to read up on the Formatter Documentation as it will help you understand it better and it provides a full list of available conversion characters.

Gavin Ralston
Gavin Ralston
28,770 Points
Gavin Ralston
Gavin Ralston
28,770 Points

No reason to add another answer here, as you covered the differences that the question is probably looking for.

I would say that another reason to use printf() is when you want to format the output in a console app. You can add tabs, zero-fill columns to make numbers line up neatly, etc.

The println() way of doing things would be to hard code spaces and tabs and run things a hundred times til everything lined up, or writing your own functions to format strings before plugging the string into the println method.

chrisverra
chrisverra
3,760 Points
chrisverra
chrisverra
3,760 Points

as told by some guy on stack overflow:

println() prints a new blank line and then your message. printf() provides string formatting similar to the printf function in C. printf() is primarily needed when you need to print big strings to avoid string concatenaion in println() which can be confusing at times. (Although both can be used in almost all cases).

Eg. int a = 10;int b = 20;

println("a: " + a + " b: " + b); //Tedious String Concatenation

printf("a: %d b: %d\n", a, b); // Output using string formatting.

While printf() enables you to print fractional outputs up to any decimal place in a single line, the same task using println() can get very complex.

Eg. printf("%.6f",x); // prints x up to 6 decimal places.

hope this helps