by In Javascript, there is a handy function replace() for String Object. We can easily replace the sub-string with new string and also regular expression in available. Replace may be case-sensitive or case insensitive. Also global replacement can be obtained using this function.
Syntax
string.replace(regex/substring,replacetext)
replace() function takes two parameters.
- regex/substring : Regular expression or a substring.
- replacetext : What the word will be replaced with. This needs to be a string.
Example
var mystr="Hello user !";
mystr.replace("user",'Sachin');
Its output is:
Hello Sachin !
To perform case insensitive search we use ‘/i’ in the regex
For example
var mystr="Hello user !"; mystr.replace(/user/i,'Sachin');
var mystr="Hello User !"; mystr.replace(/user/i,'Sachin');
In both case output would be same.
Now for global replace ‘/g’ is used.
var mystr="Hello user ! Thanks for logging in user."; mystr.replace(/user/g,'Sachin');
Its output is:
Hello Sachin ! Thanks for logging in Sachin.
To obtain global, case insensitive search we need to use ‘g’ and ‘i’ together.
var mystr="Hello user ! Thanks for logging in User."; mystr.replace(/user/gi,'Sachin');
Its output is:
Hello Sachin ! Thanks for logging in Sachin.
