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2.9 STRINGS IN JAVASCRIPT
Strings are a data type used for storing text, and in JavaScript, they are treated as objects with distinct
properties and methods. A string consists of characters, which can be letters, numbers, special symbols, or
even spaces. You can define strings using either single or double quotation marks.
In a string, each character is associated with an index, starting from 0. This index can be positive or negative,
where the positive index counts from the beginning of the string, and the negative index counts from the end.
Positive index
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
H E L L O J A V A S C R I P T
-16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1
Negative index
A string object consists of properties and methods.
For example, to find the length of a string, use the built-in length property.
var str = "Hello, World!";
var lengthOfString = str.length;
document.write (lengthOfString);
Output: 13
For example, to get each charater of a string by using length of string with a for loop.
var str = "Hello, World!";
for (var i = 0; i < str.length; i++) {
document.write (str[i] + “ “);
}
Output: H e l l o , W o r l d !
2.10 STRING PROPERTIES AND METHODS
You can also use various string methods in JavaScript to work with strings:
Method/ Description Example
Property
length Returns the string’s length. document.write("Welcome".length)
Output: 7
slice() Extracts a part of a string and returns it as a var str = "Hello World";
new string. var result = str.slice(0, 5);
document.write(result);
Output: Hello
substring() It extracts the string using the starting and var str = "JavaScript";
ending positions as parameters. If you leave var result = str.substring(4, 10);
the ending position blank, the string will be document.write(result);
extracted from beginning to end. Output: Script
222 Touchpad Web Applications (Ver. 2.0)-XII

