JavaScript String Methods You should know | JavaScript Tutorial

JavaScript String Methods You should know  | JavaScript Tutorial

In this javascript string methods tutorial. We will explain the most useful and important javascript string methods. Javascript string methods help to work with strings in javascript.

In this javascript string methods tutorial. We will explain the most useful and important javascript string methods. Javascript string methods help to work with strings in javascript.

We will demonstrate javascript string methods like javascript string replace, javascript string contains, javascript string length, javascript string concatenation, javascript string substring, remove the character from string javascript, javascript string uppercase, javascript string lowercase, string trim, tostring method, a match in the string, split string in javascript,
javascript string substr, trim string, array to comma-separated string, etc

We need to know some of the most important and useful javascript string methods.

Let’s see JavaScript String Methods

Important String Methods in javaScript

  • Length Method
  • toLocaleLowerCase() Method
  • toLocaleLowerCase() Method
  • indexOf() Method
  • search() Method
  • slice() Method
  • substring() Method
  • substr() Method
  • replace() Method
  • includes() Method
  • concat() Method
  • charAt() Method
  • charCodeAt() Method
  • lastIndexOf() Method
  • trim() Method
  • match() Method
  • split() Method
  • toString() Method
  • valueOf() Method

1. length() Method

It is used to count the number of characters in a string javascript.

Example

var str = "Hello Morioh";
var x = str.length;

Output

// return 
12

2. toLocaleLowerCase() Method

The javascript toLocaleLowerCase() is used to changed string into lower case.

Example

var str = "Hello Morioh";
var res = str.toLocaleLowerCase();

Output

// return
hello morioh

3. toLocaleUpperCase() Method

The javascript toLocaleUpperCase () is used to changed string into upper case.

Example

var str = "Hello Morioh";
var res = str.toLocaleUpperCase();

Output

// return
HELLO MORIOH

4. indexof() Method

The indexof () method returns the first position of a specified value in a string.

Example

var txt = "Connecting with Programmers and Developers all over the World";
 var test = txt.indexOf("over");

Output

// return 
47

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5. search() Method

The javascript search () method searches a string for the specified value, and returns the status of the match.

Example

var str = "Hello Morioh";
var res = str.search("Morioh");

Output

//Return
6

6. slice() Method

The slice () method removes the parts of a string and returns the extracted parts to a new string.

Use the Start and End Ultimate to specify the part of the string that you want to remove.

Example

var str = "JavaScript String Methods"; 
var res = str.slice(0, 10);

Output

// return
JavaScript

7. substring() Method

The Javascript substring() method is used to removes the characters from one string, between two specified indices, and returns the new substring.

Example

var str = "JavaScript String Methods"; 
var res =  str.substring(1, 4);

Output

//return
ava

8. substr() Method

A string substr() method begins on the character in the specified position, and returns the specified number of characters.

Example

var str = "JavaScript String Methods"; 
var res =  str.substr(1, 4);

Output

//return
avaS

9. replace() Method

The Javascript replace() changes the defined value to an another value:

Example

var str = "JavaScript String Methods"; 
var res = str.replace("Methods", "Tutorial");

Output

// return
JavaScript String Tutorial

10. includes() Method

The includes() method is used to determine whether a string contains the characters of a specified string or not. If is exist return true or not return false.

Example

var str = "Hello world, my name is morioh.";
var res = str.includes("name");

Output

// return 
True

11. concat() Method

The concat() method is used for join two or more strings.

Example

var str1 = "Hello ";
var str2 = "morioh!";
var res = str1.concat(str2);

Output

// return
Hello morioh!

12. charAt() Method

The Javascript charAt() is used to take a character to a described index location:

Example

var txt = "Hello Dev";
var res = txt.charAt(0);

Output

// return
H

13. charCodeAt() Method

The charCodeAt() method returns the Unicode of the character at a specified index in a string:

Example

var str = "TEST";
str.charCodeAt(0); 

Output

// return
84

14. lastIndexOf () Method

The lastIndexOf() the method returns the index of the last occurrence of a specified text in a string:

Example

var str = "Your are talented dev";
var pos = str.lastIndexOf("dev");

Output

// return
18

16. trim() Method

The javascript trim() method removes whitespace from both sides of a given string:

Example

var str = "        javascript trim() method removes whitespace        ";
alert(str.trim());

Output

// return
javascript trim() method removes whitespace

match() Method

The match() method searches a string for a match against a regular expression, and returns the matches, as an Array object.

Example

 var str = "lopersum lopersum lopersum lopersum."; 
 var res = str.match(/sum/g);

Output

// return
 sum,sum,sum,sum

17. split Method

The javascript split method, which is used to convert string to an array:

Example

var str = "1,2,3,4,5";
var arr = str.split(",");
document.write(arr[0]);
document.write("<br>");
document.write(arr[1]);
Output
// return
1
2

toString() Method

The javascript toString() method returns the value of a String object.

Example

var str = "javaScript World!";
var res = str.toString();

Output

// return
javaScript World!

18. valueOf() Method

The javascript valueOf() method, which is used to gets the primitive value of a String object.

Example

var str = "javaScript World!";
 var res = str.valueOf();

Output
// return
javaScript World!

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For those who don't know, I'm a full stack web developer who has been in the industry for over 5 years now. There is a lot of things I have learned along the way and I'd like to share that knowledge with anyone wanting to learn!

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JavaScript Tutorial: if-else Statement in JavaScript

JavaScript Tutorial: if-else Statement in JavaScript

This JavaScript tutorial is a step by step guide on JavaScript If Else Statements. Learn how to use If Else in javascript and also JavaScript If Else Statements. if-else Statement in JavaScript. JavaScript's conditional statements: if; if-else; nested-if; if-else-if. These statements allow you to control the flow of your program's execution based upon conditions known only during run time.

Decision Making in programming is similar to decision making in real life. In programming also we face some situations where we want a certain block of code to be executed when some condition is fulfilled.
A programming language uses control statements to control the flow of execution of the program based on certain conditions. These are used to cause the flow of execution to advance and branch based on changes to the state of a program.

JavaScript’s conditional statements:

  • if
  • if-else
  • nested-if
  • if-else-if

These statements allow you to control the flow of your program’s execution based upon conditions known only during run time.

  • if: if statement is the most simple decision making statement. It is used to decide whether a certain statement or block of statements will be executed or not i.e if a certain condition is true then a block of statement is executed otherwise not.
    Syntax:
if(condition) 
{
   // Statements to execute if
   // condition is true
}

Here, condition after evaluation will be either true or false. if statement accepts boolean values – if the value is true then it will execute the block of statements under it.
If we do not provide the curly braces ‘{‘ and ‘}’ after if( condition ) then by default if statement will consider the immediate one statement to be inside its block. For example,

if(condition)
   statement1;
   statement2;

// Here if the condition is true, if block 
// will consider only statement1 to be inside 
// its block.

Flow chart:

Example:

<script type = "text/javaScript"> 

// JavaScript program to illustrate If statement 

var i = 10; 

if (i > 15) 
document.write("10 is less than 15"); 

// This statement will be executed 
// as if considers one statement by default 
document.write("I am Not in if"); 

< /script> 

Output:

I am Not in if
  • if-else: The if statement alone tells us that if a condition is true it will execute a block of statements and if the condition is false it won’t. But what if we want to do something else if the condition is false. Here comes the else statement. We can use the else statement with if statement to execute a block of code when the condition is false.
    Syntax:
if (condition)
{
    // Executes this block if
    // condition is true
}
else
{
    // Executes this block if
    // condition is false
}


Example:

<script type = "text/javaScript"> 

// JavaScript program to illustrate If-else statement 

var i = 10; 

if (i < 15) 
document.write("10 is less than 15"); 
else
document.write("I am Not in if"); 

< /script> 

Output:

i is smaller than 15
  • nested-if A nested if is an if statement that is the target of another if or else. Nested if statements means an if statement inside an if statement. Yes, JavaScript allows us to nest if statements within if statements. i.e, we can place an if statement inside another if statement.
    Syntax:
if (condition1) 
{
   // Executes when condition1 is true
   if (condition2) 
   {
      // Executes when condition2 is true
   }
}

Example:

<script type = "text/javaScript"> 

// JavaScript program to illustrate nested-if statement 

var i = 10; 

if (i == 10) { 

// First if statement 
if (i < 15) 
	document.write("i is smaller than 15"); 

// Nested - if statement 
// Will only be executed if statement above 
// it is true 
if (i < 12) 
	document.write("i is smaller than 12 too"); 
else
	document.write("i is greater than 15"); 
} 
< /script> 

Output:

i is smaller than 15
i is smaller than 12 too
  • if-else-if ladder Here, a user can decide among multiple options.The if statements are executed from the top down. As soon as one of the conditions controlling the if is true, the statement associated with that if is executed, and the rest of the ladder is bypassed. If none of the conditions is true, then the final else statement will be executed.
if (condition)
    statement;
else if (condition)
    statement;
.
.
else
    statement;


Example:

<script type = "text/javaScript"> 
// JavaScript program to illustrate nested-if statement 

var i = 20; 

if (i == 10) 
document.wrte("i is 10"); 
else if (i == 15) 
document.wrte("i is 15"); 
else if (i == 20) 
document.wrte("i is 20"); 
else
document.wrte("i is not present"); 
< /script> 

Output:

i is 20