JS determines whether a string contains a string, finds a substring in the string object, IndexOf

var Cts = "Bbltext";

if (Cts.indexof ("Text") > 0)
{
Alert (' The CTS contains the text string ');
}
IndexOf Usage:


Returns the character position of a substring within a string object for the first time.

Strobj.indexof (substring[, StartIndex])

Parameters
Strobj

Required option. A String object or literal.

SubString

Required option. The substring to find in the string object.

Starindex

Options are available. The integer value that indicates the index at which to start the lookup within a String object. If omitted, it is searched from the beginning of the string.

Description
The IndexOf method returns an integer value that indicates the starting position of the substring in the string object. If no substring is found, 1 is returned.

If the startindex is negative, then startindex is treated as zero. If it is larger than the maximum character position index, it is treated as the largest possible index.

Performs a lookup from left to right. Otherwise, the method is the same as lastIndexOf.



IndexOf ignoring case for JavaScript


The IndexOf function method in JavaScript returns an integer value that indicates where the substring of a string object begins. If no substring is found, 1 is returned. If the startindex is negative, then startindex is treated as zero. If it is larger than the maximum character position index, it is treated as the largest possible index.


The IndexOf function performs a lookup from left to right. Otherwise, the method is the same as lastIndexOf.

The following example illustrates the use of the IndexOf function method.

function Indexdemo (str2) {   var str1 = "Babebibobubabebibobu"   var s = str1.indexof (str2);   return (s);}