Remove substring from string javascript: To remove a substring from a string, use the replace() function with the substring and an empty string as inputs, for example, gvn_str.replace (“example”, “”).
The replace() function returns a new string that removes the first occurrence of the specified substring.
Let us now see some of the below examples to understand this concept more clearly.
Removing a Substring From a String using JavaScript
1)Removing the first occurrence of ‘hello’ from a given string
// Give the string as static input and store it in a variable. const gvn_str = 'hello,hello,Btechgeeks'; // Removing the first occurrence of 'hello' from a given string // using the replace() function const remove_firststoccur = gvn_str.replace('hello', ''); console.log(remove_firststoccur);
Output:
,hello,Btechgeeks
2)Removing All occurrences of ‘hello’ from a given string
// Give the string as static input and store it in a variable. const gvn_str = 'hello,hello,Btechgeeks'; // Removing all occurrences of 'hello' from a given string // using the replaceAll() function const remove_all_occur = gvn_str.replaceAll('hello', ''); console.log(remove_all_occur);
Output:
,,Btechgeeks
3) Removing the first occurrence of hello from a given string using regex
// Give the string as static input and store it in a variable. const gvn_str = 'hello,hello,Btechgeeks'; // Removing first occurrence of hello from a given string // using regex and replace() function const removing_usingRegex = gvn_str.replace(/hello/, ''); console.log(removing_usingRegex);
Output:
,hello,Btechgeeks
4)Removing all occurrences of ‘hello’ from a given string using regex
// Give the string as static input and store it in a variable. const gvn_str = 'hello,hello,Btechgeeks'; // Removing all occurrences of 'hello' from a given string // using regex and replace() function const removeAllOccur_regex = gvn_str.replace(/hello/g, ''); // Print it on the console console.log(removeAllOccur_regex);
Output:
,,Btechgeeks
string.replace() function:
Remove substring javascript: The String.replace() function accepts the following two parameters:
- A substring of the string that we wish to match.
- Replacement for the first match.
Here we provided an empty string as the replacement since we want to remove the substring.
NOTE:
The replace method returns a new string rather than changing the old string. Strings in JavaScript are immutable.
string.replaceAll() function:
Javascript remove substring from string: Use the string.replaceAll() function to remove all occurrences of a substring from a string.
To delete all occurrences of a substring from a string, use the replaceAll() method with the substring as the first parameter and an empty string as the second.
The replaceAll method will return a new string that removes all occurrences of the substring.
The replaceAll() function takes the same 2 arguments as the replace() method takes
- The search string
- The replacement for each match.
Example
JS remove substring from string: The forward slashes / / indicate the start and end of the regular expression. Within the regular expression, we have a character class [] that matches all digits from 0 to 9. The first example replaces the first occurrence of a digit in the string with an empty string.
Approach:
- Give the string as static input and store it in a variable.
- Remove the first occurrence of any number between 0 to 9(included) from a given string using regex and replace it with an empty string using replace() function
- Print the result on the console.
- Remove All the occurrences of any number between 0 to 9(included) from a given string using regex and replace it with an empty string using replace() function.
- The Exit of the Program.
Below is the implementation:
// Give the string as static input and store it in a variable. const gvn_str = '1, one, 5, 9'; // Remove first occurrence of any number between 0 to 9(included) // from a given string using regex and replace it with an empty // string using replace() function const removeFstOccur_regex = gvn_str.replace(/[0-9]/, ''); // Print the result on console console.log(removeFstOccur_regex); // Remove All the occurrences of any number between 0 to 9(included) // from a given string using regex and replace it with an empty // string using replace() function const removeAllOccur_regex = gvn_str.replace(/[0-9]/g, ''); console.log(removeAllOccur_regex );
Output:
, one, 5, 9 , one, ,
Explanation:
Here in the first case, 1 is a number between 0 to 9(both included) hence it is replaced with an empty string. Removing only the first occurence keep the rest numbers undisturbed. In the second case, 1, 5, 9 are the numbers in a range 0 to 9, hence all of them are replaced with an empty string. Removing all the occurences
NOTE:
We can also replace it with any other string instead of an empty string
Example
// Give the string as static input and store it in a variable. const gvn_str = '1, one, 5, 9'; // Remove first occurrence of any number between 0 to 9(included) // from a given string using regex and replace it with "@" symbol // using replace() function const removeFstOccur_regex = gvn_str.replace(/[0-9]/, '@'); // Print the result on console console.log(removeFstOccur_regex); // Remove All the occurrences of any number between 0 to 9(included) // from a given string using regex and replace it with "@" symbol // using replace() function const removeAllOccur_regex = gvn_str.replace(/[0-9]/g, '@'); console.log(removeAllOccur_regex );
Output:
@, one, 5, 9 @, one, @, @