Computers take things literally. Like, literally. So much that there are things actually called literals.
Literally.
"Hello, World" is a literal. A text literal to be precise.
A text literal contains letters and numbers and is denoted by a pair of quotation marks. The quotes mark the beginning and the end of the literal.
When you run a statement like println() it is looking for something called a string. A string is another word for text. Think of it like a sequence of letter beads on a string.
When you provide a string to a statement that uses a string, it will do something with it. In the case of println() it will print it to the screen, and then move to the next line.
So, if you have the following statements:
System.out.println("Hello");
System.out.println("World");This would output as:
Hello
World
Displaying both on two lines.
But there is another statement you can use, print(). This works the same way, but you don’t move to the next line after the text displays.
So, if you have the these statements:
System.out.print("Hello");
System.out.print("World");This would output as:
HelloWorld
Putting both characters on the same line.
Text literals can contain special characters as well. Take the previous example:
System.out.print("Hello");
System.out.print("World");If you wanted to include a new line in the text literal itself, you can add it using the two-letter sequence \n.
This is called the newline character. And will create a line break in your text:
System.out.print("Hello\n");
System.out.print("World");Is essentially the same as:
System.out.print("Hello\nWorld");And displays this on the screen:
Hello
World
How about this one?
If you wanted to display the following line, how would you do it?
Mike said, "Hey!"
This line of text has a quote in it, so if we created a text literal with it we would have:
"Mike said, "Hey!""
But the computer, again, is dumb. So, it will think that the quote before the H in Hey is the end of the literal.
Not what we wanted.
To get around this, we can use a escape sequence to tell the program that the quotes around Hey are part of the literal, not the boundaries of it:
"Mike said, \"Hey\""
Now the slash quote two-character sequence can allow the literal to include the quote.
There are others you can use too, including the tab space sequence.
The tab sequence, \t adds a tab space in your text. This is sometimes helpful to align things into columns if you get the right sequence set up.
Like this one:
"First\tMiddle\tLast"
"R.\tDouglas\tWinnie"
This would display as:
First Middle Last
R. Douglas Winnie
The tab space shifts over to help line things up when you stack statements on top of one another.