Dart .toStringAsPrecision()

In Dart, .toStringAsPrecision() is a method used to convert a number to a double. It returns a string representation of that value with a specified precision of significant digits.

Syntax

number.toStringAsPrecision(int precision)

• number: A double-precision floating-point number to be converted to a string representation.
• precision: Specifies the number of significant digits in the resulting string representation of the double-precision floating-point number. It must be an integer between 1 and 21, inclusive.

Example

The following example illustrates how the .toStringAsPrecision() method is utilized to convert this number to a double and returns a string representation of that value:

void main() {
  String a1 = 1.toStringAsPrecision(2);
  print("Output = " + a1);
  String a2 = 1e15.toStringAsPrecision(3);
  print("Output = " + a2);
  String a3 = 1234567.toStringAsPrecision(9);
  print("Output = " + a3);
}

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The above code produces the following output:

Output = 1.0
Output = 1.00e+15
Output = 1234567.00

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Note:: To determine the type of the output at runtime, use the .runtimeType property.