651required validation, 325–327
styling validations, 330
validating numbers and ranges, 329
validating URL input, 327–328
value attribute (<option> element), 320
value types, 67, 138
values
described, 67
determining for variables, 83
determining if same type and equal, 84
retrieving for attributes, 153
return, 73
setting for colors, 166–171
<var> element, 35, 217
variables
assigning function expressions to, 75
case sensitivity, 72
converting to different types, 78–80
counter, 86
creating environment for, 73
described, 71
determining values of, 83
examining in debugger, 104–105
global, 77–78
JavaScript support, 66
local, 77–78
naming, 72–73
retries, 85–86
scoping, 77–78
statements and, 71–73
working with functions, 73–77
Vehicle Identification Number (VIN), 365
versioning, IndexedDB, 591
versions
including information in manifest files, 609
verifying for jQuery, 369
<video> element
autoplay attribute, 441
configuring, 441
controls attribute, 441, 450type attribute