Underscore.js is a JavaScript library that makes operations on arrays, string, objects much easier and handy.
The _.noop() function is used to return “undefined” irrespective of the arguments passed to it.
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 global variable.
Syntax:
_.noop();
Parameters: It takes optional parameter of any type.
Return Value: This function returns the value of type undefined.
Example 1:
<!DOCTYPE html> < html > < head > < script src = </ script > </ head > < body > < script > let str = new String(_.noop()) console.log(`String is ${str}`) let obj = new Object(_.noop()) console.log(`Object is ${obj.Object}`) let int = _.noop() console.log(`Integer is ${int}`) let arr = new Array(_.noop()) console.log(`Array is ${arr[0]}`) </ script > </ body > </ html > |
Output:
Example 2:
<!DOCTYPE html> < html > < head > < script src = </ script > </ head > < body > < script > let val = undefined; let val2 = _.noop(); console.log(val === val2) if (val == val2) console.log( `val and val2 are equal`); else console.log( `val and val2 are not equal`); </ script > </ body > </ html > |
Output:
Example 3: Passing parameters to the _.noop() function.
<!DOCTYPE html> < html > < head > < script src = </ script > </ head > < body > < script > let func = (para1) => { console.log(para1) } console.log("output: ") func(_.noop("some value")); // Pass function as parameter console.log("output: ") console.log(_.noop(func)) console.log("output: ") console.log(_.noop(func())) </ script > </ body > </ html > |
Output: