Expressions
One of C's distinguishing
characteristics is its emphasis on expressions formulas that show how to
compute a value rather than statements. The simplest expressions are variables
and constants. A variable represents a value to be computed as the program
runs: a constant represents a value that doesn't change. More complicated
expressions apply operators to operands (which are themselves expressions). In
the expression a + (b * c). the +
operator is applied to the operands a and (b
* c), both of which are expressions in iheir own right.
Operators are the basic tools for
building expressions, and C has an unusually rich collection of them. To start
off, C provides the rudimentary operators that are found in most programming
languages:
Arithmetic operators, including
addition, subtraction, multiplication, and division.
Relational
operators to perform comparisons such as “1 is greater than 0.”
Logical operators to build
conditions such as “1 is greater than 0 and i is less than 10.”
But C doesn't stop here; it goes on
to provide dozens of other operators. There are so many operators, in fact,
that we'll need to introduce them gradually over the first twenty chapters of
this book. Mastering so many operators can be a chore, but it's essential to
becoming proficient at C.
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