HTML and CSS Reference
In-Depth Information
EXAMPLE
9.30 (
CONTINUED
)
document.write("The search() method found \"dad\" at
position "+ index +"<br />");
4
var mysubstr=straddr.substr(index,3)
;
document.write("After replacing \"dad\" with \"POP\" <br />");
5
document.write(
straddr.replace(mysubstr,"POP")
+"<br />");
</script>
</small>
</font>
</body>
</html>
EXPLANATION
1
An e-mail address is assigned to the string variable
straddr
.
2
The
replace()
method takes two arguments, the search string and the replacement
string. If the substring
Daniel
is found, it is replaced with
Jake
.
3
The
search()
method takes a substring as its argument and returns the first posi-
tion where a substring is found in a string. In this example the substring
dad
is
searched for in the string
DanielSavage@dadserver.org
and is found at position 13.
4
The
substr()
method returns the substring found at position 13, 3 in the string,
DanielSavage@dadserver.org
:
dad.
5
The substring
dad
is replaced with
POP
in the string (see Figure 9.35).
Figure 9.35
The
search()
and
replace() String
methods: Output from Example 9.30.
Now that we've travelled this far in JavaScript, have you wondered how to format a float-
ing-point number when you display it, as you can with the
printf
function in C or Perl?
Well, the
Number
object, like the
String
object, gives you properties and methods to handle
and customize numeric data. The
Number
object is a wrapper for the primitive numeric
values (see Chapter 2, “Script Setup”), which means you can use a primitive number type