Q:

How do you print a dollar sign $ in Dart

I need to actually print a Dollar sign in Dart, ahead of a variable.  For example:
void main()
{
  int dollars=42;
  print("I have $dollars."); // I have 42.
}

I want the output to be:  I have $42.  How can I do this?  Thanks.

A:

Dart strings can be either raw or ... not raw (normal? cooked? interpreted? There isn't a formal name). I'll go with "interpreted" here, because it describes the problem you have.
In a raw string, "$" and "\" mean nothing special, they are just characters like any other.
In an interpreted string, "$" starts an interpolation and "\" starts an escape.
Since you want the interpolation for "$dollars", you can't use "$" literally, so you need to escape it:

int dollars = 42;
print("I have \$$dollars.");

If you don't want to use an escape, you can combine the string from raw and interpreted parts:
int dollars = 42;
print(r"I have $" "$dollars."); 

Two adjacent string literals are combined into one string, even if they are different types of string.

A:

You can use a backslash to escape:
int dollars=42;
print("I have \$$dollars."); // I have $42.

When you are using literals instead of variables you can also use raw strings:
print(r"I have $42."); // I have $42.

