Javascript удалить символ в строке

удалить символ из строки js

Для удаления символа из строки можно воспользоватьтся методом replace() , передав первым аргументом символ, который нужно удалить, а вторым — пустую строку » .

Метод replace() поддерживает работу с регулярными выражениями. Если первым аргументом передать регулярное выражение с флагом g , то из строки будут удалены все символы, совпадающие с регулярным выражением, а иначе — только первый.

Предположим, нам необходимо удалить из номера телефона все ошибочно попавшие в него специальные символы:

const phoneNumber = '+7* $999% 123& 45# 67'; const regExp = /\*|%|#|&|\$/g; console.log(phoneNumber.replace(regExp, '')); // => +7 999 123 45 67 

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How to Remove a Character from String in JavaScript?

JavaScript provides users with a number of methods for manipulating strings, transforming them, and extracting useful information from them. Sometimes we write multiple lines of code to make modifications, search for a character, replace a character, or remove a character from a string. All of these operations become tough to complete, so JavaScript provides techniques to make the job easier. These methods make it simple for users to manipulate and alter strings.

Introduction

In JavaScript, removing a character from a string is a common method of string manipulation, and to do so, JavaScript provides a number of built-in methods which make the job easier for the users.

Removing a Character from String in JavaScript

JavaScript String replace()

The replace() method is one of the most commonly used techniques to remove the character from a string in javascript. The replace() method takes two parameters, the first of which is the character to be replaced and the second of which is the character to replace it with. This method replaces the first occurrence of the character. To remove the character, we could give the second parameter as empty.

Using a replace() Method with a Regular Expression

Unlike the previous approach, this one removes all instances of the chosen character. Along with the global attribute, a regular expression is utilized instead of the string. It will select every instance of the string and allow you to remove it.

Removing Character from String Using substring()

This method will take two indexes and then returns a new substring after retrieving the characters between those two indexes, namely starting index and ending index. It will return a string containing characters from starting index to ending index -1 . If no second parameter is provided, then it retrieves characters till the end of the string.

The above code will remove the character present at the 1st index, which is e in this case.

Remove Character from String in Javascript Using substr()

This method will take a starting index and a length and then returns a new substring after retrieving the characters from starting index till the length provided. If no second parameter is provided, then it retrieves characters to the end of the string.

Removing Character from String Using slice()

This method is the same as the substring method, but with a distinction that if starting index > ending index, then substring will swap both the arguments and returns a respective string, but the slice will return an empty string in that case.

Using split() Method

Another way to eliminate characters in JavaScript is the split() method, which is used along with the join() method. To begin, we utilize the split() method to extract the character we want, which returns an array of strings . These strings are then joined using the join() method.

Conclusion

• Javascript provides various methods for string manipulation, and one of the very common methods for string manipulation is removing a character in the string.
• Javascript provides various methods like replace() , substring() , substr() , split() , slice() etc which makes the task of removing a character in a string very easy.

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4 Ways to Remove Character from String in JavaScript

Looking to remove the character from string in JavaScript? Let’s discuss remove method details in this post.

Using substring() method

JavaScript substring() method retrieves the characters between two indexes and returns a new substring.

Two indexes are nothing but startindex and endindex.

Let’s try to remove the first character from the string using the substring method in the below example.

function removeFirstCharacter() < var str = 'tracedynamics'; str = str.substring(1); console.log(str); >Output: racedynamics 

Now let’s remove the last character from the string using the substring method in the below example.

function removeLastCharacter() < var str = 'tracedynamics'; str = str.substring(0,str.length-1); console.log(str); >Output: tracedynamic 

the length property is used to determine the last element position.

As per the output above, you can see that specified first and last characters are removed from the original string.

With substr() method

substr() method will retrieve a part of the string for the given specified index for start and end position.

Let’s remove the first character from string using substr function in the below example.

function removeFirstCharacter() < var str = 'tracedynamics'; str = str.substr(1); console.log(str); >Output: racedynamics 

Now let’s see how to remove the last character from string using substr function in the below example.

function removeLastCharacter() < var str = 'tracedynamics'; str = str.substr(0,str.length-1); console.log(str); >Output: tracedynamic 

using below JavaScript code, we can also remove whitespace character from a string.

function removeWhiteSpaceCharacter() < var str = 'tracedynamics '; str = str.substr(0,str.length-1); console.log(str); >Output: tracedynamics 

As you can see from the above function, in the input string value there is whitespace at the end of the string which is successfully removed in the final output.

Using slice() method

slice() method retrieves the text from a string and delivers a new string.

Let’s see how to remove the first character from the string using the slice method.

function removeFirstCharacter() < var str = 'tracedynamics'; str = str.slice(1); console.log(str); >Output: racedynamics 

Now let’s remove the last character from string using the slice method.

function removeLastCharacter() < var str = 'tracedynamics'; str = str.slice(0,str.length-1); console.log(str); >Output: tracedynamic 

Using replace() method

replace() method is used to replace a specified character with the desired character.

This method accepts two arguments or parameters.

The first argument is the current character to be replaced and the second argument is the new character which is to be replaced on.

Let’s see how to replace the first character in a string using the replace function.

function replaceFirstCharacter() < var str = 'tracedynamics'; str = str.replace('t','T'); console.log(str); >Output: Tracedynamics 

Now let’s replace the last character in JavaScript string using replace function.

function replaceLastCharacter() < var str = 'tracedynamics'; str = str.replace('s','S'); console.log(str); >Output: tracedynamicS 

Now let’s replace specified character in a string using the replace method.

function replaceCharacter() < var str = 'tracedynamics'; str = str.replace('d','D'); console.log(str); >Output: traceDynamics 

Also we can apply regular expression(regex)in the replace method to replace any complex character or special character in the string.

Regular expressions(regex) are also useful when dealing with a line break, trailing whitespace, or any complex scenarios.

Using above JavaScript methods, we can also remove characters on string array, line break, trailing whitespace, empty string, Unicode character, double quotes, extra spaces, char, parenthesis, backslash

We can remove multiple characters by giving the specified index for start and end position.

To conclude this tutorial, we covered various types of implementation to remove a character from string using JavaScript.

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