CS 110 Notes – Basics II 1
Copyright C. Tanner 2009
• More on Assignment operators
o Variable = expression;
o Evaluate the expression and then store the result as the value of variable
o Compound operators
+= -= /= *= %=
Variable compound operator expression;
a += 5 Î a = a+5;
a*= 5 Î a = a * 5;
a *= 5 + c; Î a = a * (5+c);
o Page 111 #20 Rewrite the assignment statement using a compound
operator
a). x = 2 * x;
b). x = x + y -2;
c). sum=sum + num;
do d,e for non-collected homework
• Increment/Decrement Operators
o a = a+1;
o a = a-1;
o common, often used operation
o built in machine instructions to cover these inc, dec
o a++; Î a = a+1;
o a--; Î a = a-1;
o syntax allows ++a or a++, --a or a—
o can use it within an expression
a = b-- + c++ - d;
a = --b + ++c –d;
these two are *not* equivalent
never ++ or -- except in a stand alone statement
• Math Library
o Collection of methods for all elementary math functions
o Such as, pow, sqrt, floor, ceil, abs, sin, cos etc
o To use qualify the method with Math.
o . – qualifying operator (member access operator)
