JS intercept string substr and substring

The

Substr method
Returns a substring of the specified length starting at the specified position. The
Stringvar.substr (start [, length])
parameter
Stringvar
must be selected. The string literal or string object to extract the substring. The
Start
option is required. The starting position of the desired substring. The index of the first character in the string is 0.
Length
is optional. The number of characters that should be included in the returned substring.
Description
If length is 0 or negative, an empty string is returned. If this argument is not specified, the substring continues to the end of the stringvar. The following example of
example
shows the use of the Substr method.
Copy code code as follows:
function Substrdemo () {
var s, SS;//DECLARE variable.
var s = "The rain in Spain falls mainly the plain.";
SS = S.substr (12, 5);//Get substring.
Return (ss);//Back to "Spain".
}

The

Substring method
Returns a substring at the specified position in a string object.
Strvariable.substring (Start, end)
' string Literal '. Substring (start, end)
parameter
Start
indicates the starting position of the substring, which Starting from 0.
End
Indicates the ending position of the substring, starting at 0. The
Description
Substring method returns a string containing a substring from start to the last (not including end). The
substring method uses the smaller values in both start and end as the starting point for substrings. For example, strvar.substring (0, 3) and strvar.substring (3, 0) will return the same substring.
If start or end is NaN or negative, replace it with 0. The length of the
substring equals the absolute value of the difference between start and end. For example, the length of the substring returned in strvar.substring (0, 3) and strvar.substring (3, 0) is 3. The following example of
example
shows the use of the substring method.
Copy code code as follows:
function Substringdemo () {
var ss;//DECLARE variable.
var s = "The rain in Spain falls mainly in the plain ...";
SS = s.substring (12, 17);//Fetch substring.
Return (ss);//returns a substring.
}