Expression building for Unit conversion
Building of expressions can be done for different units using different divisors.
Learning Objectives
 Making simple formulas.
 Reuse of left hand side variable for recalculation with new units in a formula.
Source Code

Run Output
Code Understanding
double d,t,s; //Three double variables declared
d=1200;t=400;
d assigned 1200 which is distance in meters and t assigned 400 which is time in seconds
s=d/t;
This formula will thus give speed in m/s in variable s based on values filled in d and t variable.
System.out.println(“Speed (in m/s) = “+s);
Speed in m/s will be printed
s=(d/1000)/(t/3600);
Since the s above has already been printed for value in m/s we can again build a new formula for km/hr speed and fill its value in s. For km/hr formula we simply divide meter value in d with 1000 as 1 km=1000 m and t with 3600 as 1 hour = 3600 seconds. For this division we do it in separate brackets so that precedence of operator rules are properly followed.
System.out.println(“Speed (in km/hr) = “+s);
System.out.println(“Speed (in km/hr) = “+s);
With this we print the speed in km/hr as the s will now contain value based on recalculation based on new formula.
Notes
 Reuse of variables should normally be done only when it is being used for similar purposes.
 Reuse of variables may be avoided if the use of variables is required for displaying all values together.
Suggested Filename(s): ExpUnitConversion.java
sunmitra Created: 5Mar2018  Updated: 5Mar2018