Question with code equation

[xl JAMKA lx]

so, I was doing homework and The code for C#

celsius = (fahrenheit - 32) * 5 / 9 ;       //equation to convert Fahrenheit to Celsius

//celsius = 5 /9 * (fahrenheit - 32);  <----Doesn't work.

can someone explain why the second one doesn't work?

Homework is done and turned in.  I just wanna know why it doesn't work.

Edited September 10, 2019 by xl JAMKA lx

[Homer]

Order of Operations (Source)

Assuming your fahrenheit variable is likely a double or a float.

Lets say its a float for example:

 

celsius = (fahrenheit - 32) * 5 / 9

(fahrenheit - 32) is executed first and results in a float value

Next the float value is * 5, which results in a float type value again

Next the float value is / 9, which results in a float type value again and thats the end result.

 

celsius = 5 /9 * (fahrenheit  - 32)

(fahrenheit - 32) is executed first because of highest Precedence (Source)

However next, (5 / 9) is executed and returns an integer 0

5/9 performs an integer division—that is, it always discards the fractional part—so it will always return 0

 

The integer type issue can be fixed by:

celsius = 5f / 9 * (fahrenheit  - 32)

or if fahrenheit is a double, then:

celsius = 5.0 / 9 * (fahrenheit  - 32)

[xl JAMKA lx]

ah okay, yeah Fahrenheit was defined as a double variable