Underscore.js is a library in javascript that makes operations on arrays, string, objects much easier and handy. _.isMap() function is used to check whether the given object is javascript Map or not.
Note: It is very necessary to link the underscore CDN before going and using underscore functions in the browser. When linking the underscore.js CDN The “_” is attached to the browser as a global variable.
Syntax:
_.isMap(object);
Parameters :
- object : It is any javascript object such as array, string, maps, set etc.
Returns : It returns the boolean value. If the object is a Map of javascript it returns true otherwise false is returned by the function.
Few Examples are given below for a better understanding of the function.
Example 1:
When an array is given the output is false.
<!DOCTYPE html> <html lang="en"> <head> <meta charMap="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> <script src= </script> </head> <body> <script> //creating a array of size 2 using constructor var obj= new Array(2); //filling array with value 10 obj.fill(10); //using the underscore.js function _.isMap() var isMap= _.isMap(obj); console.log(isMap) //If the given object is Map it prints the object is Map. if(isMap) console.log(`The ${obj} is the Map of Javascript.`) else console.log(`The ${obj} is not the Map of Javascript.`) </script> </body> </html> |
Output:
Example 2:
When a Map is given it returns true.
<!DOCTYPE html> <html lang="en"> <head> <meta charMap="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> <script src= </script> </head> <body> <script> //creating a Map using constructor var obj= new Map(); //using the underscore.js function _.isMap() var isMap= _.isMap(obj); console.log(isMap) //If the given object is Map it prints the object is Map. if(isMap) console.log(`The ${obj} is the Map of Javascript.`) else console.log(`The ${obj} is not the Map of Javascript.`) </script> </body> </html> |
Output:
Example 3:
When giving an object as a parameter the output is false
<!DOCTYPE html> <html lang="en"> <head> <meta charMap="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> <script src= </script> </head> <body> <script> //creating a Javascript Object using constructor var obj= new Object(); obj={ "a":1, "b":2 } //using the underscore.js function _.isMap() var isMap= _.isMap(obj); console.log(isMap) //If the given object is Map it prints the object is Map. if(isMap) console.log(`The ${obj} is the Map of Javascript.`) else console.log(`The ${obj} is not the Map of Javascript.`) </script> </body> </html> |
Output:
