There are five methods to compare strings.


1.Equality == True if operands are the same; otherwise false
e.g.
var sVal = "this"; if (sVal == "this) // true

 

2.Strict equality === True if operands are the same, and the same data type;
otherwise false 
e.g.
     var sVal = "this"; 
     var sVal2 = new String("this"); 
     if (sVal === sVal2) // not true 
3.Inequality != True if operands are not the same; otherwise false 
e.g.
     var sVal = "this"; 
     if (sVal == "that") // true 
4.Strict inequality !== True if operands are not the same, or are not the same data type; otherwise false 
e.g.
     var sVal = "this"; 
     var sVal2 = new String("this"); 
     if (sVal !== sVal2) // true 
5.String method: localeCompare. 
     The localeCompare method takes one parameter, a string, which is compared against the string value to which it is attached. The method returns a numeric value equal to 0 if the two strings are the same; –1 if the string parameter is lexically greater than the original string; 1 otherwise: 
     var fruit1 = "apple"; 
     var fruit2 = "grape"; 
     var i = fruit1.localeCompare(fruit2); // returns -1 
 
 
Test Code:

window. { 

var sVal = "this"; 
var sVal2 = new String("this"); 
//if (sVal === sVal2) 
alert("sVal == sVal2:"+(sVal == sVal2));   
alert("sVal === sVal2:"+(sVal === sVal2));   
alert("sVal != sVal2:"+(sVal != sVal2)); 
alert("sVal !== sVal2:"+(sVal !== sVal2)); 
alert("sVal.localeCompare(sVal2):"+sVal.localeCompare(sVal2)); 

}