Converting String to double

Part of the Fundamentals section of Coddy's Dart journey — lesson 84 of 94.

The double.parse() method converts a string representation of a decimal number into a double value.

Create a string containing a decimal number:

String priceAsString = '19.99';

Convert the string to a double using double.parse():

double price = double.parse(priceAsString);
print(price);

After executing the above code, the output will be:

19.99

You can use the converted double in calculations:

String discountAsString = '5.50';
double discount = double.parse(discountAsString);
double finalPrice = price - discount;
print('Final price: $finalPrice');

After executing the above code, the output will be:

Final price: 14.49

Challenge

Beginner

In this challenge, you'll practice converting a string to a double using double.parse(). This method converts a string representation of a decimal number into a double value.

Complete the code to convert the priceText string to a double and store it in the priceValue variable.

Cheat sheet

The double.parse() method converts a string representation of a decimal number into a double value.

String priceAsString = '19.99';
double price = double.parse(priceAsString);
print(price); // Output: 19.99

You can use the converted double in calculations:

String discountAsString = '5.50';
double discount = double.parse(discountAsString);
double finalPrice = price - discount;
print('Final price: $finalPrice'); // Output: Final price: 14.49

Try it yourself

void main() {
  // This string contains a price as text
  String priceText = "23.50";
  
  // TODO: Convert priceText to a double using double.parse()
  // and store it in the priceValue variable
  double priceValue;
  
  // This will calculate the price with tax (15%)
  double priceWithTax = priceValue * 1.15;
  
  // This will display the results
  print("Original price: \$${priceText}");
  print("Price as a double: ${priceValue}");
  print("Price with 15% tax: \$${priceWithTax.toStringAsFixed(2)}");
}