ECMAScript 1 (ES1) - 1997

ECMAScript 1 (ES1), released in 1997, was the first edition of the ECMAScript language specification, which aimed to standardize the core features of JavaScript to ensure consistency across different web browsers. This standardization was crucial for web development, as it addressed compatibility issues and provided a solid foundation for the future development of the language. Below, we'll revisit some of the key features introduced in ES1 and provide examples to illustrate these concepts.

Key Features and Examples

1. Variables and Data Types

ES1 defined several basic data types, including Number, String, Boolean, Object, Function, undefined, and null.

var number = 1; // Number
var text = "Hello, world!"; // String
var flag = true; // Boolean
var obj = { name: "John" }; // Object
var func = function() { return "Hello from function"; }; // Function
var undef; // undefined
var empty = null; // null

2. Basic Syntax and Operators

It established the syntax for declarations, expressions, and operators.

var sum = 1 + 2; // Addition operator
var isEqual = (sum === 3); // Equality operator

3. Control Structures

ES1 introduced control structures such as if statements, for and while loops.

if (sum === 3) {
  console.log("Sum is 3");
}

for (var i = 0; i < 3; i++) {
  console.log("Loop", i);
}

var count = 0;
while (count < 3) {
  console.log("Count", count);
  count++;
}

4. Functions

Functions in ES1 could be declared to encapsulate reusable code.

function add(a, b) {
  return a + b;
}

var result = add(1, 2);
console.log(result); // Outputs: 3

5. Objects and Arrays

ES1 defined objects and arrays, allowing for complex data structures.

var person = { firstName: "John", lastName: "Doe" }; // Object
var numbers = [1, 2, 3]; // Array

console.log(person.firstName); // Outputs: John
console.log(numbers[0]); // Outputs: 1

6. Standard Library

The standard library included built-in objects and functions, such as Math, Date, and string manipulation functions.

var maxNumber = Math.max(1, 2, 3);
console.log(maxNumber); // Outputs: 3

var now = new Date();
console.log(now); // Outputs the current date and time

var uppercaseText = text.toUpperCase();
console.log(uppercaseText); // Outputs: "HELLO, WORLD!"

ECMAScript 1 laid the groundwork for JavaScript's future by standardizing the syntax, types, and basic functionalities of the language. While it was just the beginning, with many more features and improvements to come in later editions, ES1 was crucial for ensuring that JavaScript could develop into a consistent, reliable, and powerful programming language for web development.

1.1 ECMAScript 1 (ES1) - 1997