JavaScript Syntax
When approaching any language that involves high levels of programming, the first rule of thumb is mastering its grammar which is called Syntax. Each sequence of code that forms requests has its own structural rules which are called syntax. In this way, Javascript is similar to English, as it has its own particular grammar that needs to be followed.The language structures used in JavaScript are simple and easy to learn, which makes it an attractive language for novices. The fundamental syntax of a JavaScript statement is outlined in the following way:
Statements:
In most cases, JavaScript source code consists of an indefinite number of statements, each of which analyzes something. A statement is usually issued for a computer to do a specific task. In JavaScript, every statement ends with a ; On the other hand, semicolons are not mandatory in JavaScript although it is a good convention to place them at the end of every statement as a rule.Whitespace:
Canonical English sentences contain proper spacing between words, and for JavaScript code, proper spacing and indentation also improve the readability of the code. While these items, such as spaces, tabs, or newlines, are mostly not regarded by the JavaScript language interpreter, developers employ them for improving the code's legibility.Comments:
When writing code using JavaScript, it is possible to add comments on the code. These are short pieces of text which the interpreter does not execute but is meant to describe what the code does. There are two types of comments:Single-line comments: Which uses the two slash marks
// .Multi-line comments: Which uses the slash and asterisk marked
/ and the asterisk and slash marked / .Case Sensitivity:
JavaScript is case sensitive; a variable or a function that is written in lower case is distinct from a function or a variable that appears in upper case. For instance, the variable and Variable would be regarded as two different identifiers.Case in point: Blocks that contain code in JavaScript are enclosed in a pair of curly braces. These blocks could be such as a function, a loop or simply a conditional statement. Without proper use of the curly braces, it becomes quite difficult to understand where the limits of such code blocks are drawn.
Knowing some of the basic syntax details, you are now in a position to begin writing a reasonable JavaScript code. So, we now proceed to variables, which are very useful when it comes to holding data and changing it.
Rules Governing the Use of JavaScript Variables
For JavaScript, the term variable refers to an electronic address where one will keep the information. Put in simple terms, a variable can be viewed as an entity that can take different forms in the shape of a number, string, or even an object. The use of variables empowers data and techniques in the program to be organized and structured.Variable Declaration:
In JavaScript, you can create a variable by using one the three keywords: var, let, const. So, each word has a function:Var: The var keyword was the most reliable means of initializing a variable in JavaScript. However, it has been largely superseded by let and construction purposes in modern JavaScript due to its function-scoping behavior.
Let: The let keyword is used when you want to create variables which will later be re-declared. It is block-scoped hence the variable is only available within a section of code in which it was created.
Const: To create a constant - a variable that cannot be assigned a new value after it has been assigned a value only once use the const keyword. It is also block scoped.
Variable Value Assignment:
Once you have declared a variable, you can give it a value using the assignment operator (=). The value can be typed in as string, number, boolean, array and many others. For instance:Variable Assignment Example
let ethicalBasesValue = 30;
const person = "John" Variable Types:
Variables are at the core of any programming language. In javascript, we have different data types which a variable can be assigned. These include but are not limited to:Results obtained from user input, for example, Hello world which can be stored in a variable as a string: string variables
Mathematical values, for example, 36 or even a fraction like 0.3333: number variables
True or false – dependencies of a variable: boolean variables.
Types of objects – variables can contain several data types that are stored in a list.
Associative arrays – pairs of values under one name, enabling the user to store data or rather make definitions: object variables.
In order to write any sophisticated javascript code, it would be crucial to know how variables are declared as well as used. Now, let us take time to look at javascript operators in particular.
Operators in JavaScript
Operators in java allow users to execute certain commands and perform specific tasks using variables and values of various kinds. The language incorporates various sorts of operators, each designed to accomplish a certain objective.Arithmetic Operators:
This type of operator is designed for mathematical operations and performs various tasks over mathematical sets of numbers. This type of operator comprises:
The function of this operator is to sum two statistical values. If a user wants to add two numbers together they would use this instruction: addition operator.
This operates by decreasing arithmetic values. A lesser value is obtained by taking away another value over which a user has control.: subtraction operator.
This is a function ensuring that 2 values and their correlation are maintained mathematically. This is an operator when a user wants to multiply two values.: multiplication operator.
The operator works or operates when a user wishes to divide one value or value set by another. It divides 1 set of statistics by another set of statistics.: division operator.
This is another mathematical operator that lets the user identify the remainder left after one set of numbers has been divided by another.: modulus operator.
The function of this operator is to add one to a specified number. It's usually applied when a user wants to increase a value by one unit.: increment operator.
When a value falls below one, this operator comes into use. It is sometimes manipulated when a user wants to decrease the value of a number by one.: decrement operator.
Assignment Operators:
To put it simply, this class of operators is responsible for giving a value to variables. The simplest of the assignment operators is the equal sign = , but there are other assignment operators that perform a combination of assignment and other work: += : It adds a value to a variable and assigns it the new value of the variable. -= : It takes away a value from a variable and assigns it the assigned value. *= : It takes a variable, multiplies it by a value and assigns the new value. /= : Does it define the concept of division in words. It takes a variable and divides it by the value assigned.Comparison Operators:
This is the type of operators that check variables, get two values or more of them, and return either true or false. Among the comparison operators we can find: == : this symbol represents equality in mathematics. === : it is known as strict equality. It checks the value as well as the variable type. != : is a sign of non – similarity and when placed hierarchically in an expression denotes not equality. > : "greater than" in mathematics means one figure is larger than the other figure symbolised by the greater than sign. < : this symbol represents the opposite of the greater than sign. > = : in reverse studies, this is a combination of greater than or equal to sign. <= : Greater than or equal to sign with a reverse meaning.Logical Operators:
These are used when there are multiple conditions and the requirement is to merge them together. There are also some prominent logical operators: && (AND): this is a logical conditional operator. It is only true when both conditions are true. || (OR): The logic behind it is that there are multiple conditions but at least one of those conditions needs to be true. ! (NOT): This is a logical negation operator, its meaning in simple terms would be reversed.
