- `thing`

- : Anything to be converted to a string.

When `String()` is called as a function (without [`new`](/en-US/docs/Web/JavaScript/Reference/Operators/new)), it returns `value` [coerced to a string primitive](/en-US/docs/Web/JavaScript/Reference/Global_Objects/String#string_coercion). Specially, [Symbol](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol) values are converted to `"Symbol(description)"`, where `description` is the [description](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/description) of the Symbol, instead of throwing.

When `String()` is called as a constructor (with `new`), it coerces `value` to a string primitive (without special symbol handling) and returns a wrapping {{jsxref("String")}} object, which is **not** a primitive.

String function and String constructor produce different results:

const a = new String("Hello world"); // a === "Hello world" is false

const b = String("Hello world"); // b === "Hello world" is true

a instanceof String; // is true

b instanceof String; // is false

typeof a; // "object"

typeof b; // "string"

Here, the function produces a string (the {{Glossary("primitive")}} type) as promised.

However, the constructor produces an instance of the type String (an object wrapper) and

that's why you rarely want to use the String constructor at all.

`String()` is the only case where a symbol can be converted to a string without throwing, because it's very explicit.

```js example-bad

const sym = Symbol("example");

`${sym}`; // TypeError: Cannot convert a Symbol value to a string

"" + sym; // TypeError: Cannot convert a Symbol value to a string

"".concat(sym); // TypeError: Cannot convert a Symbol value to a string

```js example-good

const sym = Symbol("example");

String(sym); // "Symbol(example)"

{{Specifications}}

{{Compat}}