Comparing strings in a case-insensitive manner means comparing them without taking care of the uppercase and lowercase letters.
Here are some common approaches to compare the case-insensitive string in javascript:
- Using toUpperCase() function
- Using toLowerCase() function
- Using localCompare()
- Using regular expression
Approach 1: JavaScript toUpperCase() function:
The str.toUpperCase() function converts the entire string to Upper case. This function does not affect any of the special characters, digits, and alphabets that are already in upper case.
Syntax:
string.toUpperCase()
Example: This example uses toUpperCase() function to compare two strings.
Javascript
let str1 = "this iS neveropenForGeeKs";let str2 = "This IS GeeksfOrneveropen";console.log(str1)console.log(str2)function myGeeks() { let areEqual = str1.toUpperCase() === str2.toUpperCase(); console.log(areEqual);}myGeeks() |
this iS neveropenForGeeKs This IS GeeksfOrneveropen true
Approach 2: JavaScript toLowerCase() function:
The str.toLowerCase() function converts the entire string to lower case. This function does not affect any of the special characters, digits, and alphabets that are already in lowercase.
Syntax:
string.toLowerCase()
Example: This example uses the toLowerCase() function to compare two strings.
Javascript
let str1 = "this iS neveropen";let str2 = "This IS GeeksfOrneveropen";console.log(str1)console.log(str2)function myGeeks() { let areEqual = str1.toLowerCase() === str2.toLowerCase(); console.log(areEqual);}myGeeks() |
this iS neveropen This IS GeeksfOrneveropen false
Approach 3: Using localCompare()
The localeCompare() method in JavaScript compares strings based on the current locale, returning a value indicating their relative order.
Syntax:
referenceString.localeCompare(compareString);
Example: In this example, we will use the localeCompare function to compare two strings.
Javascript
let str1 = "this iS neveropen";let str2 = "This IS GeeksfOrneveropen";console.log(str1)console.log(str2)function myGeeks() { let areEqual = str1.localeCompare(str2, undefined, { sensitivity: 'accent' }); console.log(areEqual === 0 ? true : false);}myGeeks() |
this iS neveropen This IS GeeksfOrneveropen false
Approach 4: Using regular expression:
A regular expression (regex) is a sequence of characters that define a search pattern.
Syntax:
let regex = new RegExp(pattern, flags);
Example: In this example, we will use the regular expression to compare two strings.
Javascript
let str1 = "this iS neveropenforGeeks";let str2 = "This IS GeeksfOrneveropen";console.log(str1)console.log(str2)function myGeeks() { let pattern = new RegExp(str1, 'gi'); let result = pattern.test(str2); console.log(result ? true : false);}myGeeks() |
this iS neveropenforGeeks This IS GeeksfOrneveropen true
