JavaScript Replace a Substring in String
To replace the occurrence(s) of a substring in a string with a new value in JavaScript, call replace() method on this string, and pass the search string and replacement string as arguments.
Syntax
The syntax to replace a substring searchValue
with a new value replaceValue
in this string str
is
str.replace(searchValue, replaceValue)
replace() method returns a new string with the replacement(s) done, and keeps the original string str
unchanged.
Examples
Replace the First Occurrence
In the following example, we take three strings: str, searchValue, and replaceValue. We will use replace() method to replace the first occurrence of searchValue with replaceValue in str.
index.html
<!DOCTYPE html> <html lang="en"> <body> <pre id="output"></pre> <script> var str = 'apple banana apple orange'; var searchFor = 'apple'; var replaceWith = 'mango'; var result = str.replace(searchFor, replaceWith); var output = ''; output += 'Input String : ' + str; output += '\nOutput String: ' + result; document.getElementById('output').innerHTML = output; </script> </body> </html>
Replace All Occurrences using Global Modifier
In the following example, we take a string str and replace ‘apple’ with ‘mango’ at all the occurrences using global(g) modifier.
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<!DOCTYPE html> <html lang="en"> <body> <pre id="output"></pre> <script> var str = 'apple banana apple orange'; var result = str.replace(/apple/g, 'mango'); var output = ''; output += 'Input String : ' + str; output += '\nOutput String: ' + result; document.getElementById('output').innerHTML = output; </script> </body> </html>
Conclusion
In this JavaScript Tutorial, we learned how to replace a substring with a new value in this string in JavaScript, using replace() method, with examples.