Chapter 4 Quick Reference
 To Do this Example Determine whether two values are equivalent Use the == or != operator. `answer == 42` Compare the value of two expressions Use the <, <=, >, or >= operator. `age >= 21` Declare a Boolean variable Use the bool keyword as the type of the variable. `bool inRange;` Create a Boolean expression that is true only if two other conditions are true Use the && operator. ```inRange = (lo <= number)   &&  (number <= hi);``` Create a Boolean expression that is true if either of two other conditions is true Use the || operator. ```outOfRange = (number < lo)    ||  (hi < number);``` Run a statement if a condition is true Use an if statement. ```if (inRange)   process();``` Run more than one statement if a condition is true Use a block. ```if (seconds == 59) { seconds = 0; minutes++; }``` Associate different statements with different values of a controlling expression Use a switch statement. ```switch (current) { case '<':  ... break;  default : ...   break; } ```