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2.6. Scalar Operators and Functions

The most common operation on a scalar variable is assignment , which is the way to give a value to a variable. The Perl assignment operator is the equal sign (much like C or FORTRAN), which takes a variable name on the left side and gives it the value of the expression on the right, like so:

```\$a = 17;     # give \$a the value of 17
\$b = \$a + 3; # give \$b the current value of \$a plus 3 (20)
\$b = \$b * 2; # give \$b the value of \$b multiplied by 2 (40)```

Notice that last line uses the \$b variable twice: once to get its value (on the right side of the =), and once to define where to put the computed expression (on the left side of the =). This is legal, safe, and in fact, rather common. In fact, it's so common that we'll see in a minute that we can write this using a convenient shorthand.

You may have noticed that scalar variables are always specified with the leading \$. In shell programming, you use \$ to get the value, but leave the \$ off to assign a new value. In Java or C, you leave the \$ off entirely. If you bounce back and forth a lot, you'll find yourself typing the wrong things occasionally. This is expected. (Our solution was to stop writing shell, awk, and C programs, but that may not work for you.)

A scalar assignment may be used as a value as well as an operation, as in C. In other words, \$a=3 has a value, just as \$a+3 has a value. The value is the value assigned, so the value of \$a=3 is 3. Although this may seem odd at first glance, using an ...

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