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JavaScript Symbol() Constructor
  • Last Updated : 08 Mar, 2021

The Symbol() constructor is used to create a new symbol. The Symbol() constructor returns a value of the type of symbol with static properties. Every time we call the constructor a unique symbol is created. A Symbol constructor is a primitive data type having no object or no methods which are generally used as an identifier.

Synrax:

Symbol(str)

Arguments: The only argument is an optional string that is used for debugging but not to access the symbol. It means every time we call Symbol() constructor a unique symbol is created.

Return value: The Symbol() constructor returns a value of the type of symbol. And every time a unique symbol is returned.

Example 1: Below is the example of the Symbol() constructor.



Javascript




<script>
  function func() {
    // symbol without any parameter
    const sym1 = Symbol();
  
    // symbol with parameter
    const sym2 = Symbol(9);
  
    // symbol with string
    const sym3 = Symbol("GFG");
  
    console.log(sym2.toString());
  
    // Type of symbol 1
    console.log(typeof sym1);
  
    // Check symbol is equal to "GFG" or not
    console.log(sym3=="GFG");
  }
  func();
  
 </script>

Output:

Symbol(9)
symbol
false

Example 2: In this example, the constructor creates a new primitive symbol const sym1 = Symbol();

Javascript




<script>
function func() {
  // symbol without any parameter
  const sym1 = Symbol();
  
  console.log(sym1);
}
func();
</script>

Output:

Symbol()

Example 3: In this example, the constructor creates a new primitive symbol with an argument const sym2 = Symbol(9);

Javascript




<script>
function func() {
  // symbol with a parameter
  const sym2 = Symbol(9);
  
  console.log(sym2.toString());
}
func();
</script>

Output:

Symbol(9)

Example 4: In this example, the constructor creates a new primitive symbol with a string argument const sym3 = Symbol("GFG");

Javascript




<script>
function func() {
  // symbol without a string parameter
  const sym3 = Symbol("GFG");
  
  console.log(sym3);
}
func();
</script>

Output:

Symbol(GFG)

Example 5: In this example, we compare the return symbol with the string and return true if both are equal, otherwise, it returns false. Since the Symbol() constructor returns only a symbol, its output is false, console.log(sym3 == "GFG");.

Javascript




<script>
function func() {
  
  // symbol with string
  const sym3 = Symbol("GFG");
    
  // Check symbol is equal to "GFG" or not
  console.log(sym3=="GFG");
}
func();
</script>

Output:

false
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