CODEWITHSUNDEEP
javascript
bsod99
bsod99

Reputation: 1297

Extract substring from between two words

I'm trying to find a clean way to extract a substring from between two other substrings.So far I can do it based on targeting a specific character, but not a string. E.g (this doesn't work)

 var element = "Firstconstantmystring_lastconstant";
 var mySubString = element.substring(
                            element.lastIndexOf("Firstconstant") + 1,
                            element.lastIndexOf("_lastconstant")
                        );

I'm trying to extract "mystring" from the full string. I know that "Firstconstant" and "_lastconstant" will always be the same. Grateful for any help.

Upvotes: 0

Views: 180

Answers (3)

Shohanur
Shohanur

Reputation: 126

function substringBetween(s, a, b) {
var p = s.indexOf(a) + a.length;
return s.substring(p, s.indexOf(b, p));
}

var element = "Firstconstantmystring_lastconstant;";
var mySubString = substringBetween(element,'Firstconstant','_lastconstant')

console.log({mySubString })

Upvotes: 1

Mamun
Mamun

Reputation: 68933

You should take the length from the first:

var element = "Firstconstantmystring_lastconstant";
var mySubString = element.substring(
                            "Firstconstant".length,
                            element.lastIndexOf("_lastconstant")
                        );
console.log(mySubString);

Upvotes: 1

shreyasm-dev
shreyasm-dev

Reputation: 2834

You can use a regular expression.

var string = 'Firstconstantmystring_lastconstant'
console.log(string.match(/(?<=Firstconstant)[\s\S]*(?=_lastconstant)/))

This will return an array with the first element being the result you want if there is a match, or null if there is no match.

Resources:

Upvotes: 3

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