javascript

Chapter 5: Reference Types
In this code, the string “ yellow ” is compared to three different values: “ brick ” , “ yellow ” , and “ zoo ” .
Because “ brick ” comes alphabetically before “ yellow ” , localeCompare() returns 1 ; “ yellow ” is
equal to “ yellow ” , so localeCompare() returns 0 for that line; and “ zoo ” comes after “ yellow ” , so
localeCompare() returns – 1 for that line. Once again, because the values are implementation - specific,
it is best to use localeCompare() as shown in this example:
function determineOrder(value) {
var result = stringValue.localeCompare(value);
if (result < 0){
alert(“The string ‘yellow’ comes before the string ‘” + value + “’.”);
} else if (result > 0) {
alert(“The string ‘yellow’ comes after the string ‘” + value + “’.”);
} else {
alert(“The string ‘yellow’ is equal to the string ‘” + value + “’.”);
}
}
determineOrder(“brick”);
determineOrder(“yellow”);
determineOrder(“zoo”);
By using this sort of construct, you can be sure that the code works correctly in all implementations.
The unique part of localeCompare() is that an implementation ’ s locale (country and language)
indicates exactly how this method operates. In the United States, where English is the standard language
for ECMAScript implementations, localeCompare() is case - sensitive, determining that uppercase
letters come alphabetically after lowercase letters. However, this may not be the case in other locales.
The fromCharCode() Method
There is one method on the String constructor: fromCharCode() . This method ’ s job is to take one or
more character codes and convert them into a string. Essentially, this is the reverse operation from the
charCodeAt() instance method. Consider this example:
alert(String.fromCharCode(104, 101, 108, 108, 111)); //”hello”
In this code, fromCharCode() is called on a series of character codes from the letters in the word
“ hello ” .
HTML Methods
The web - browser vendors recognized a need early on to format HTML dynamically using JavaScript.
As a result, they extended the specification to include several methods specifically designed to aid in
common HTML formatting tasks. The following table enumerates the HTML methods. However, be
aware that typically these methods aren ’ t used, because they tend to create nonsemantic markup.
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