Whitespace and Basic Formatting

Whitespace and Basic Formatting

Whitespace means the "empty" characters: spaces, tabs, and newlines. C++ shrugs at most of them.

The compiler ignores whitespace

Outside of strings, extra spaces and newlines don't change behaviour:

int x = 5;

int     x   =   5;

Both compile and do the same thing. But wow - the second one is unpleasant!

One place whitespace counts

Inside a string literal, spaces are part of the text:

cout << "hello world"; // keeps the space
cout << "helloworld";  // different text!

Also, you generally can't split a keyword or identifier by spaces: in t is not int.

What the whitespace is for: readability

Indentation - moving nested code in with tabs or spaces - tells you at a glance what belongs inside a block:

int main() {
    if (age > 5) {
        cout << "Big kid!";
    }
}

The inner line is indented one more level because it belongs to the if. Even though the compiler doesn't need this, your future self does.

Style notes

• Pick one style (spaces vs tabs, brace on the same line) and stick to it.
• Consistent formatting makes bugs easy to spot, since odd lines "pop out".
• Many teams use a tool (clang-format) to auto-format everyone's code.

TL;DR

• Whitespace = spaces, tabs, and newlines; the compiler ignores it (except inside strings).
• Indentation has no effect, but it's great for readability.
• Indent nested code to show it "belongs to" the block above.
• Stay consistent with your formatting everywhere.