HomeLanguagesJavascriptJavaScript String isWellFormed() Method

JavaScript String isWellFormed() Method

JavaScript String.isWellFormed() method is used to check if the string contains a lone surrogate or not. A lone surrogate is a string that contains Unicode characters in the range 0xD800–0xDBFF and 0xDC00–0xDFFF. It returns trues if the lone surrogate is not present. If the string is not well-formed it will give an error if we use the encodeURI() method on it.

Syntax:

isWellFormed()

Parameters: It does not take any parameter

Return Value: A boolean, true if no lone surrogate is present, and false if the lone surrogate is present.

Example 1: This example uses the isWellFormed() method on strings.

Javascript




const str1 = "ab\uD800";
const str2 = "new\uD800";
const str3 = "hello";
 
console.log(str1.isWellFormed());
console.log(str2.isWellFormed());
console.log(str3.isWellFormed());


Output:

false
false
true

Example 2: This example will perform the encodeURI function only on well-formed strings.

Javascript




const badFormed = "ab\uD800";
const wellFormed = "hello";
 
function checkFormation(str) {
    if(str.isWellFormed()){
        console.log(encodeURI(str))
    }
}
checkFormation(wellFormed);
checkFormation(badFormed);


Output:

hello

Supported Browsers:

  • Chrome
  • Edge
  • Opera
  • Safari

We have a complete list of Javascript string methods, to check those please go through this Javascript String reference article.

Whether you’re preparing for your first job interview or aiming to upskill in this ever-evolving tech landscape, neveropen Courses are your key to success. We provide top-quality content at affordable prices, all geared towards accelerating your growth in a time-bound manner. Join the millions we’ve already empowered, and we’re here to do the same for you. Don’t miss out – check it out now!
RELATED ARTICLES

6 COMMENTS

Most Popular

Dominic
32688 POSTS0 COMMENTS
Milvus
131 POSTS0 COMMENTS
Nango Kala
7057 POSTS0 COMMENTS
Nicole Veronica
12198 POSTS0 COMMENTS
Nokonwaba Nkukhwana
12293 POSTS0 COMMENTS
Shaida Kate Naidoo
7182 POSTS0 COMMENTS
Ted Musemwa
7447 POSTS0 COMMENTS
Thapelo Manthata
7160 POSTS0 COMMENTS
Umr Jansen
7150 POSTS0 COMMENTS