[Chapter 3] 3.2.131 scalar
Author: Larry Wall, Tom Christiansen & Randal L. Schwartz
Date: 1999-07-02T01:53:38Z

#

| Chapter 3 Functions |

### 3.2.131 scalar

    scalar EXPR

This pseudo-function may be used within a `LIST` to force `EXPR` to be evaluated in scalar context when evaluation in list context would produce a different result.

For example:

    local($nextvar) = scalar <STDIN>;

prevents `<STDIN>` from reading all the lines from standard input before doing the assignment, since assignment to a local list provides a list context. (Without the use of scalar in this example, the first line from `<STDIN>` would still be assigned to `$nextvar`, but the subsequent lines would be read and thrown away. This is because the assignment is being made to a list - one that happens to be able to receive only a single, scalar value.)

Of course, a simpler way with less typing would be to simply leave the parentheses off, thereby changing the list context to a scalar one:

    local $nextvar = <STDIN>;

Since a print function is a `LIST` operator, you have to say:

    print "Length is ", scalar(@ARRAY), "\n";

if you want the length of `@ARRAY` to be printed out.

One never needs to force evaluation in a list context, because any operation that wants a list already provides a list context to its list arguments for free. So there's no list function corresponding to scalar.

3.2.130 s/// |  | 3.2.132 seek