如何检查一个javascript字符串是否在其他两个字符串之间

Question

Lets say I had a string like so:

let string = "one two three four five red five six seven eight nine"

How could I return a boolean (either true or false ) that tells the user if the word red is between the two words five (In this case a boolean of true would be returned as red is between the two fives )?

Example where I am using this code

I am making a text editor where the user types code in a text area.

I am going to return the value of the text editor as a variable. I would like to check if the user is inputting code within two <script> tags.

Here is the code for the textarea :

<textarea class="form-control slideIn" id="input" spellcheck="false" wrap="off" placeholder="Get Creative!"></textarea>

And this code gets the value of the textarea :

const code = document.getElementById("input").value;

Does this help?

Answer 1

You can generate a simple regex like this one five(.*)five

With a bit of configuration, it could become something like

function isBetween(mystring, between, left, right)
{
    // define the regex which will become : "/five(.*)five/g"
    const regex = new RegExp( left + ' (.*) ' + right, 'g');

    // execute the regex
    const m = regex.exec(mystring);

    // if there is a result and the (.*) pattern matched sthg
    // then check if its equel to red
    return m && m[1] ? (m[1] === between) : false;
}

isBetween("one two three four five red five six seven eight nine", "red", "five", "five");