Why does division result in zero instead of a decimal?

Question

Teaching myself C and finding that when I do an equation for a temp conversion it won\'t work unless I change the fraction to a decimal. ie,

tempC=(.555*(tempF

Answer 1

When you do 5/9, 5 and 9 are both integers and integer division happens. The result of integer division is an integer and it is the quotient of the two operands. So, the quotient in case of 5/9 is 0 and since you multiply by 0, tempC comes out to be 0. In order to not have integer division, atleast one of the two operands must be float.

E.g. if you use 5.0/9 or 5/9.0 or 5.0/9.0, it will work as expected.