Algorithms For Dummies

 

   

  PART 1 

 Getting Started

Comparing data by using  

Boolean expressions

Using arithmetic to modify the content of variables is a kind of data manipulation. 

To determine the effect of data manipulation, a computer must compare the cur-

rent state of the variable against its original state or the state of a known value. In 

some cases, detecting the status of one input against another is also necessary. All 

these operations check the relationship between two variables, so the resulting 

operators are relational operators, as shown in Table 4-5.

Sometimes a relational operator can’t tell the whole story of the comparison of 

two values. For example, you might need to check a condition in which two sepa-

rate comparisons are needed, such as 

MyAge > 40

 and 

MyHeight < 74

. The need 

to add conditions to the comparison requires a logical operator of the sort shown 

in Table 4-6.