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JavaScript Symbol

The JavaScript Symbol is a function that is used to identify the object properties.

Points to remember

1. A Symbol() method always return a unique value.
2. A symbol value may be used as an identifier for object properties.
3. Symbols are immutable, just like numbers or strings.
4. Symbols cannot be typecasted to primitive data types.

Syntax

Parameters

description: It is optional. We can pass string as an argument.

JavaScript Symbol Property

Let’s see the list of JavaScript Symbol properties with their description.

Symbol.hasInstance	It is used to determine if a constructor object recognizes an object as its instance.
Symbol.isConcatSpreadable	It is used to configure if an object should be flattened to its array elements.
Symbol.match	It is a method to identify the matching of a regular expression against a string.
Symbol.prototype	It is used for produce the prototype for the symbol constructor.
Symbol.replace	It replace matched substring of a string.
Symbol.search	It returns the index within a string that matches with the regular expression.
Symbol.split	It splits a string at the indices that match the regular expression.
Symbol.toPrimitive	It is used to convert an object to its equivalent primitive value.
Symbol.unscopables	It is a well-known object property whose property name are excluded from with environment.

JavaScript Symbol Methods

Let’s see the list of JavaScript Symbol Method with their description.

Symbol.for()	It is used to search for existing symbol in a runtime-wide symbol registry with the provided key and returns if it is found. Otherwise new symbol gets created with this key.
Symbol.keyFor()	It uses the global symbol registry to look up the key for the symbol. So it doesn’t work for non-global symbols. If the symbol is not global, it won’t be able to find it and returns undefined.
Symbol.toString()	It is used to return a string representation of an object.