ES6 String methods
Es6 introduced new methods of a String object. In this blog post, I will cover the new string methods with examples.
Newly introduced String methods can be generic and Unicode methods.
Generic methods
- startsWith()
- endsWith()
- includes()
- repeat()
String.prototype.startsWith() method example
startsWith() method returns
true - if the passed string with the search string is matched from the starting index position, If the index position is specified, It checks at the nth position
false - search string is not matched.
Syntax
startsWith(searchstring,index)
The two arguments are 1. String to search - substring to be searched 2. Index position - It is a position from which a search starts. By default is zero.
const message = "This is a new string methods";
console.log(message.startsWith("This is")); // true
console.log(message.startsWith("Thias is")); // false
console.log(message.startsWith("is", 4)); // false
console.log(message.startsWith("is", 5)); // true
String.prototype.endsWith() method example
endsWith() method also takes two arguments
This method returns true if the string end is matched with another string.
Syntax
endsWith(searchstring,index)
It has two arguments
- Search string - string to search that matched from end 2. Index position - It is a position to match with the string, this is optional
const message = "This is a new string methods";
console.log(message.endsWith("methods")); // true
console.log(message.endsWith("methodsa is")); // false
console.log(message.endsWith("is", 4)); // true
console.log(message.endsWith("is", 5)); // false
String.prototype.includes() method example
This return is true if the search substring contains a string.
includes(searchstring,index)
It has two arguments
- Search string - string to be matched with the given string 2. Index position - It is starting position to begin searching the string, This is optional.
const message = "this is testing include";
console.log(message.includes("tesing")); // true
console.log(message.includes("adfadf")); // false
console.log(message.includes("is", 8)); // false
console.log(message.includes("is", 2)); // true
String.prototype.repeat() method example
This method repeats the given string a given number of times. It gives the output concatenate strings.
str.repeat(count)
parameter - the number of times to repeat the string
const message = "cloud";
console.log(message.repeat(2)); // cloudcloud
console.log(message.repeat(3)); // cloudcloudcloud
Unicode methods
es6 introduced methods for dealing with Unicode strings. Here are the methods for String.fromCodePoint String.prototype.codePointAt; String.prototype.normalize;
Conclusion
Learn new string methods examples startsWith() endsWith() includes() repeat() method.