The **`concat()` method** joins multiple strings, with a source string , nd returns a new string.

# Syntax

```
string.concat(...strings);
```

# Example 



let source = "I love";
let joinedString = source.concat("Educative.io");
console.log(joinedString);

// joining multiple string 

joinedString= source.concat(" ", "Educative.io", " and ", "JavaScript Jeep");
console.log(joinedString);


---

When we don't pass in an argument, a copy of the source string is returned. 

let source = "Educative";
let joinedString = source.concat();
console.log("Calling concat without argument. Joined string = ", joinedString);


---
If the argument passed in is not a string, then it is internally converted to a string.

console.log('calling "".concat({}) -->',"".concat({}) );
console.log('calling "".concat([]) -->',"".concat([]) );
console.log('calling "".concat(null) -->',"".concat(null) );
console.log('calling "".concat(4, 5) -->',"".concat(4, 5) );
console.log('calling "".concat(a => a) -->',"".concat(a => a) );

Instead of `concat()`, we can use the assignment operator (this is the recommended method).

let source = "I";

let joinedString = source + " Love " + "Educative.io";

console.log(joinedString);

What is String.concat() in JavaScript?

Joins multiple strings into one, returning a new string. Internally converts non-string arguments. Using the assignment operator is recommended over concat().