This is known as block-scope or lexical-scope. In most of the C-based languages, variables are created upon their declaration and exist within the block that they are declared. (Prior to ES6) var-Declarations are Hoisted to the Top of the File or Function The var-variable is peculiar! There is no local block-scope variables.ĮS6 introduces local block-scope let and const declarations. A local-function variable having the same name as a global variable shadows the global variable inside the function. They are accessible within the defining function only. Local-Function Scope: var-variables declared inside a function definition have local-function scope.They can be accessed from any part of the script. What are getters and setters for in ECMAScript 6 classes Ask Question Asked 8 years, 4 months ago Modified 1 year, 6 months ago Viewed 89k times 111 I am confused as to what the point of getters and setters are in ECMAScript 6 classes. Global Scope: var-variables declared outside functions have global scope. This chapter introduces the new features in ECMAScript 2016: JavaScript Exponentiation () JavaScript Exponentiation assignment () JavaScript Array includes () Exponentiation Operator The exponentiation operator ( ) raises the first operand to the power of the second operand.Prior to ES6, you could only use the keyword var to declare a variable.
The var, let and const Variable Declarations This article describes the new features introduced in ECMAScript version 6 (or ES6, ES2015, ES6Harmony), formerly known as "ECMA-262 ECMAScript Language Specification 2015".Īll the examples are tested under Node.js (see "Node.js How To" on how to setup and run JavaScripts).įor brevity, cleaner-looking and more meaningful codes, I omit the ending semicolons use single quote for string avoid foo-bar, i, j, k use const instead of let and var keep the sentences short and brief.
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