JavaScript method to check whether a substring is in a string_javascript tips

The example in this article describes the JavaScript method of checking whether a substring is in a string. Share it with everyone for your reference, the details are as follows:

var strnew="Hello Raghu How are u"
//Checking existence in entire string
if(strnew.indexOf("Raghu") != -1 )
{
  alert("Exists");
}
/*
Checking existence at the end of string
For example, variable result1 in the following example is assigned 
the value of true because the word "Ishmael" appears at the end of 
the string. Variable result2 is assigned a value of false because 
"Raghu" doesn't appear at the end of the string.
*/
result1 = /Raghu$/.test("Call me Raghu");
result2 = /Raghu$/.test("Call me Raghu. Some years ago");
/*
Checking existence in the begining of string
In the following example, variable result1 is assigned the value 
of true because the word "Birds" appears at the beginning of the 
string. Variable result2 is assigned the value of false because 
"Birds" doesn't appear at the beginning of the string.
*/
result1 = /^Birds/.test("Birds fly");
result2 = /^Birds/.test("Big Birds fly");

Readers who are interested in more JavaScript-related content can check out the special topics on this site: "Summary of JavaScript search algorithm techniques" and "Summary of JavaScript data structure and algorithm techniques"

I hope this article will be helpful to everyone in JavaScript programming.