JavaScript: Inline Script with SRC Attribute?
It's either one or the other, not both. The src attribute of the <script> tag has precedence over the body of the tag.
The script may be defined within the contents of the SCRIPT element or in an external file. If the
srcattribute is not set, user agents must interpret the contents of the element as the script. If thesrchas a URI value, user agents must ignore the element's contents and retrieve the script via the URI.
The HTML specification states
If the src has a URI value, user agents must ignore the element's contents and retrieve the script via the URI.
From the HTML 4 standard:
If the src attribute is not set, user agents must interpret the contents of the element as the script. If the src has a URI value, user agents must ignore the element's contents and retrieve the script via the URI.