JavaScript is the powerful language which is very useful for developing the web-based application. The HTML and CSS programming languages define the structure of the web pages and its layout whereas JavaScript plays an important role in programming its behaviour. Nowadays JavaScript is one of the most popular and used languages. It is high level interpreted runtime language and support object-oriented and programming styles so it will give more control over the browser. Through JavaScript programming language you can access the document model of browser and change the structure of web pages at runtime. The given below cheat sheet which is very useful for those who want to brush up their skills. There are many cheat sheets available for JavaScript and Jquery. You can find freelancers who know JavaScript programming language.
The syntax of JavaScript:
JavaScript is used in the program by using the JavaScript statements that are placed within the <script>……</script>. You can use this tag within your web page, but the recommendation is that you should use that within the head tags. The<sctript> allows the browser to start interpreting all the text between these tags as a script.
<script>
JavaScript code
</script>
Data Types in JavaScript:
Any programming language supports the set of data types. Following are some set of data types that can be represented and manipulated in a programming language.
Numbers ex 25, 33, 33.5
Boolean ex true or false
Strings ex “This text string.”
Variables in JavaScript
The variables in JavaScript are simply the name of a storage location, and there are two types of variables in JavaScript such as local variable and global variable. The var keyword is used to declare the variables in JavaScript.
For declaring the variables in the JavaScript there are some rules that most of the programmer should know.
The name of the letter starts with the letters (a to z or A to Z) underscore(_), or dollar($) sign.
After using the letter, you can use digits (0 to 9)
JavaScript variables are case sensitive
var x = 10;
var_value=”sonoo”;
Operators in JavaScript
The operator is the collection of symbols that allows the programmer to perform mathematical and logical operations. Following are the list of operators in JavaScript.
Arithmetic Operators
Logical Operators
Comparison Operators
Assignment Operators
Conditional Operators
Conditional Statements in JavaScript
Conditional statements allow your program to make correct decisions and perform right actions. The JavaScript programming supports conditional statements which are used to perform different actions based on different conditions. Following are the name of conditional statements. You can hire freelancers who have complete knowledge of JavaScript programming language.
If statements
If……else statements
If……else if statement
Function in JavaScript
The function allows the programmer to use the same code anywhere in your program. The function also divides the large program into some smaller and manageable functions.
<script type = “text/ javascript>
<!—
Function functionname(parameters-list)
{
Statements
}
//– >
</script>
Array in JavaScript
The array is the collection of similar type of objects, and it stores the fixed size sequential elements. Following are the syntax of Array.
Var fruits = new Array (“apple”, “pineapple”,” mango”)
Void Keyword:
The void is a very important keyword in JavaScript which is very useful as a unary operator that appears before its single operand that may be of any type.
<script type=”text/javascript”>
<!—
Void func()
Javascript : void func()
</script>
</head>
this keyword
This keyword is the confusing things for both new and skilled JavaScript developers. The keyword “this” is the current execution context of a function. This keyword gives reference to the object which calls the function. Following is the syntax of JavaScript
this
Use of this keyword in function
function f1() {
return this;
}
Math Object
For mathematical constants and functions, Math object provides the properties and methods. All the properties and methods of math are static and called using Math as objects without creating it.
var pi_val = Math.PI;
var sine_val = Math.sin(30);
Regular Expression in JavaScript
Regular expression plays an important role in matching the character combinations in strings. The JavaScript programming language uses the exec and test methods for RegExp and with a match, search, replace, and split methods of string. Following is the suffix of JavaScript regular expression. You can hire freelancers who have complete knowledge of JavaScript programming language.
G global
i case-insensitive
s single line
m multi-lines
Summary:
This article gives you information regarding the JavaScript cheat sheet. This cheat sheet covers all important concepts that the developer must. It is the cheat sheet which is very useful for those who want to brush up their JavaScript skills. Through this cheat sheet, you can easily perform programming in JavaScript
