Exercise

Create the following directory tree :

1. msg.dart

Create two fuctions the first print "Program starts" and the second print "Program ends".

2. trigo.dart

Create three functions that print the sin , cos and tan of a given number using math library.

3. cal.dart

Create two functions that print the square and the logarithm of a given number using math library.

4. main.dart

- Import msg.dart and cal.dart.
- Import trigo.dart with a perfix "trigo".
- Use all functions inside all these 3 files.

Solution:

1. msg.dart



void printStart() {

  print("Program start");

}

 

void printEnd() {

  print("Program end");

}





2. trigo.dart



import 'dart:math';

 

void printSin(double x) {

  print("sin($x) = ${sin(x)}");

}

 

void printCos(double x) {

  print("cos($x) = ${cos(x)}");

}

 

void printTan(double x) {

  print("Tan($x) = ${tan(x)}");

}





3. cal.dart



import 'dart:math';

 

void printSqrt(double x) {

  print("the sqrt of $x is ${sqrt(x)}");

}

 

void printLog(double x) {

  print("the log of $x is ${log(x)}");

}





4. main.dart



import './messages/msg.dart';

import './math/cal.dart';

import './math/trigo.dart' as trigo;

 

void main() {

  printStart();

  trigo.printSin(0.5);

  trigo.printCos(0.75);

  trigo.printTan(0.25);

  printSqrt(9);

  printLog(1);

  printEnd();

}






Program start
sin(0.5) = 0.479425538604203
cos(0.75) = 0.7316888688738209
Tan(0.25) = 0.25534192122103627
the sqrt of 9.0 is 3.0
the log of 1.0 is 0.0
Program end