Difference between revisions of "JavaScript"

From NovaOrdis Knowledge Base
Jump to: navigation, search
(Subjects)
(Things I've Found Useful While Working with Chrome Console)
 
(4 intermediate revisions by the same user not shown)
Line 10: Line 10:
  
 
* The simplest example: https://www.w3schools.com/js/js_whereto.asp
 
* The simplest example: https://www.w3schools.com/js/js_whereto.asp
 +
 +
=Things I've Found Useful While Working with Chrome Console=
 +
 +
<syntaxhighlight lang='javascript'>
 +
var a = 10;
 +
console.log(a);
 +
 +
var workersUp = function(targetCnt) {
 +
    return Cluster.workers().length == targetCnt;
 +
};
 +
</syntaxhighlight>
 +
 +
A JavaScript identifier must start with lower or upper case letter, underscore (_) or dollar ($). Subsequent characters may include digits.
 +
 +
The Underscore identifier: it is frequently used to preface the name of an object's property or method that is private.
 +
 +
https://underscorejs.org:
 +
 +
<tt>_.range(1, 100000)</tt>: a function to create flexibly numbered lists of integers: https://underscorejs.org/#range
 +
 +
<tt>_.map(list, iteratee, [context])</tt>: https://underscorejs.org/#map
 +
 +
Arrow function expression () =>. The arrow function expression is a syntactically compact alternative to a regular function expression https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions. The basic syntax:
 +
(param1, param2, …, paramN) => { statements }
 +
 +
(param1, param2, …, paramN) => expression
 +
// equivalent with:
 +
  => { return expression; }
 +
 +
When there is one parameter parentheses are optional:
 +
 +
(param) => { statements }
 +
// equivalent with:
 +
param => { statements }

Latest revision as of 23:10, 14 August 2019

Subjects

Examples

Organizatorium

Things I've Found Useful While Working with Chrome Console

var a = 10;
console.log(a);

var workersUp = function(targetCnt) {
    return Cluster.workers().length == targetCnt;
};

A JavaScript identifier must start with lower or upper case letter, underscore (_) or dollar ($). Subsequent characters may include digits.

The Underscore identifier: it is frequently used to preface the name of an object's property or method that is private.

https://underscorejs.org:

_.range(1, 100000): a function to create flexibly numbered lists of integers: https://underscorejs.org/#range

_.map(list, iteratee, [context]): https://underscorejs.org/#map

Arrow function expression () =>. The arrow function expression is a syntactically compact alternative to a regular function expression https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions. The basic syntax:

(param1, param2, …, paramN) => { statements } 
(param1, param2, …, paramN) => expression
// equivalent with:
 => { return expression; }

When there is one parameter parentheses are optional:

(param) => { statements }
// equivalent with:
param => { statements }