Javascript Strings

Latest revision as of 17:01, 11 September 2013

Although the String object is not directly supported by Yate's Javascript these methods are applicable to most non-object variables.

Note that these are not real properties of strings and cannot be enumerated!

length

Property that describes the length of a string as a decimal number.

Returns numeric length of string

x="abcd";
Engine.output(x.length);

4

charAt(pos)

Function that returns a character at a certain 0-based position in string.

Returns a string containing a single character or empty if pos is out of bounds.

x="abcd";
Engine.output(x.charAt(3));

d

indexOf(str)

Function that returns the position of a substring in another string.

Returns 0-based position of str or -1 if str is not found

x="abcd";
Engine.output(x.indexOf("bc"));

1

substr(offs,len)

Function that returns a substring.

Returns a string that starts at 0-based position offs and has at most len characters

x="abcd";
Engine.output(x.substr(1,2));

bc

substr(offs)

Function that returns a substring.

Returns a string that starts at 0-based position offs to the end of the original string

x="abcd";
Engine.output(x.substr(2));

cd

match(reg)

Function that matches a string against a Regular Expression.

Returns an Array holding the match results and some extra information:

[0] holds the whole matching string
[1]... hold the captured substrings
index holds the 0-based index of the first matching character
input holds the RegExp object used in match

If the string does not match the regular expression reg then the function returns null.

x="abc123";
m = x.match(/([0-9])/);
Engine.output((typeof m) + " index=" + m.index + " input=" + m.input);

object index=3 input=([0-9])

toLowerCase()

Function that converts a string to lower case.

Returns the string converted to lower case characters.

x="AbCd";
Engine.output(x.toLowerCase());

abcd

toUpperCase()

Function that converts a string to upper case.

Returns the string converted to upper case characters.

x="AbCd";
Engine.output(x.toUpperCase());

ABCD

trim()

Function that removes leading and trailing spaces from a string.

Returns the string with all initial and final whitespaces removed.

x="  a bc d ";
Engine.output(">" + x.trim() + "<");

>a bc d<

sqlEscape()

Function that performs SQL escaping on a string.

Note that backslash escaping is an SQL extension

x="a'b'c\\backslash";
Engine.output(x.sqlEscape());

a''b''c\\backslash

startsWith(str)

Function that checks if a string starts with a specific substring.

Returns true if str is the prefix of the string.

x="abcd";
Engine.output(x.startsWith("ab"));

true

endsWith(str)

Function that checks if a string ends with a specific substring.

Returns true if str is the suffic of the string.

x="abcd";
Engine.output(x.endsWith("bcd"));

true

split(sep)

Function that splits a string into an Array at a separator.

Returns an Array object holding the string fragments.

x="abc,def,xyz";
a=x.split(",");
Engine.output("[0]=" + a[0] + " [1]=" + a[1] + " [2]=" + a[2]);

[0]=abc [1]=def [2]=xyz

toString()

Function that converts a number to string using numbering base 10.

x=1234;
s=x.toString();
Engine.output((typeof s) + " " + s)

string 1234

toString(base)

Function that converts a number to string using a specified numbering base.

x=1234;
s=x.toString(16);
Engine.output((typeof s) + " " + s)

string 4d2

Javascript Strings

Latest revision as of 17:01, 11 September 2013

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@@ Line 13: / Line 13: @@
   '''4'''
-* <div id="charAt">'''charAt(pos)'''<div>
+* <div id="charAt">'''charAt(pos)'''</div>
 Function that returns a character at a certain 0-based position in string.
@@ Line 54: / Line 54: @@
 * <div id="match">'''match(reg)'''</div>
-Function that matches a string against a Regular Expression.
+Function that matches a string against a [http://en.wikipedia.org/wiki/Regular_expression Regular Expression].
+Returns an Array holding the match results and some extra information:
+* [0] holds the whole matching string
+* [1]... hold the captured substrings
+* index holds the 0-based index of the first matching character
+* input holds the [[Javascript_RegExp|RegExp]] object used in match
+If the string does not match the regular expression ''reg'' then the function returns '''null'''.
+ x="abc123";
+ m = x.match(/([0-9])/);
+ Engine.output((typeof m) + " index=" + m.index + " input=" + m.input);
+ '''object index=3 input=([0-9])'''
 * <div id="toLowerCase">'''toLowerCase()'''</div>
 Function that converts a string to lower case.
+Returns the string converted to lower case characters.
+ x="AbCd";
+ Engine.output(x.toLowerCase());
+ '''abcd'''
 * <div id="toUpperCase">'''toUpperCase()'''</div>
 Function that converts a string to upper case.
+Returns the string converted to upper case characters.
+ x="AbCd";
+ Engine.output(x.toUpperCase());
+ '''ABCD'''
 * <div id="trim">'''trim()'''</div>
 Function that removes leading and trailing spaces from a string.
+Returns the string with all initial and final whitespaces removed.
+ x="  a bc d ";
+ Engine.output(">" + x.trim() + "<");
+ '''>a bc d<'''
 * <div id="sqlEscape">'''sqlEscape()'''</div>
 Function that performs SQL escaping on a string.
+Note that backslash escaping is an SQL extension
+ x="a'b'c\\backslash";
+ Engine.output(x.sqlEscape());
+ '''<nowiki>a''b''c\\backslash</nowiki>'''
 * <div id="startsWith">'''startsWith(str)'''</div>
 Function that checks if a string starts with a specific substring.
+Returns true if ''str'' is the prefix of the string.
+ x="abcd";
+ Engine.output(x.startsWith("ab"));
+ '''true'''
 * <div id="endsWith">'''endsWith(str)'''</div>
 Function that checks if a string ends with a specific substring.
+Returns true if ''str'' is the suffic of the string.
+ x="abcd";
+ Engine.output(x.endsWith("bcd"));
+ '''true'''
 * <div id="split">'''split(sep)'''</div>
 Function that splits a string into an Array at a separator.
+Returns an Array object holding the string fragments.
+ x="abc,def,xyz";
+ a=x.split(",");
+ Engine.output("[0]=" + a[0] + " [1]=" + a[1] + " [2]=" + a[2]);
+ '''[0]=abc [1]=def [2]=xyz'''
 * <div id="toString">'''toString()'''</div>
 Function that converts a number to string using numbering base 10.
+ x=1234;
+ s=x.toString();
+ Engine.output((typeof s) + " " + s)
+ '''string 1234'''
 * '''toString(base)'''
 Function that converts a number to string using a specified numbering base.
+ x=1234;
+ s=x.toString(16);
+ Engine.output((typeof s) + " " + s)
+ '''string 4d2'''