typeof special operator
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typeof
Entity type evaluation.
Description
The typeof special operator returns a string representation of the unevaluated operand type.
Syntax
| Signature | Description |
|---|---|
typeof operand | Returns a string representation of the unevaluated operand type. |
typeof (operand) | Returns a string representation of the unevaluated operand type. |
Parameters
| Parameter | Description |
|---|---|
operand | The entity we wish to return the type for. |
Examples
Following are examples of the typeof special operator which stores results in an array for display.
// The typeof operator.
var typeofArray = new Array(11);
typeofArray[0] = typeof ""; // an empty string
typeofArray[1] = typeof "1"; // a string
typeofArray[2] = typeof 1; // a number
typeofArray[3] = typeof 1.1; // a decimal
typeofArray[4] = typeof NaN; // the Not-a-Number global
typeofArray[5] = typeof undefined; // the undefined global
typeofArray[6] = typeof someVariable; // an undefined varaible
typeofArray[7] = typeof true; // a boolean
typeofArray[8] = typeof false; // a boolean
typeofArray[9] = typeof typeof [1, 2 ,3]; // an object
typeofArray[10] = typeof typeof new Date(); // an object
alert(typeofArray);