CODEWITHSUNDEEP
javascriptregex
Jethro Hazelhurst
Jethro Hazelhurst

Reputation: 3285

Can get RegEx to match only certain characters /[&<>"']/g

I am looping through an array of letters and am trying to find only &, <, >, " and ' characters to replace them with their HTML entities...

Here is my code

function convertHTML(str) {

    // html entity switch block
    function entify(char){
        alert(char);
        switch (char) {
            case '&':
                return '&​amp;';
            case '<':
                return '&​lt;';
            case '>':
                return '&​gt;';
            case '"':
                return '&​quot;';
            case '\'':
                return '&​apos;';
        }
    }


    // convert string into an array
    str = str.split('');
    // loop through the array
    for (var i = 0; i < str.length; i++) {
        // compare each to the regular expression, if it matches then it needs to be replaced with an html entity
        console.log(str[i]);
        str[i] = str[i].replace(/[&<>"']/g, entify);
    }
    str = str.join('');
    console.log(str);
    return str;
}

convertHTML("&");

Unfortunately my regular expression doesn't seem to be picking up the characters and I'm not even triggering the entify function.

Why is that?

Upvotes: 1

Views: 150

Answers (2)

Djaouad
Djaouad

Reputation: 22776

Use this (which calls entify for each match using an arrow function) :

function convertHTML(str) {
    // html entity switch block
    function entify(char){
        switch (char) {
            case '&':
                return '&​amp;';
            case '<':
                return '&​lt;';
            case '>':
                return '&​gt;';
            case '"':
                return '&​quot;';
            case '\'':
                return '&​apos;';
        }
    }

    // convert string into an array
    str = str.split('');
    // loop through the array
    for (var i = 0; i < str.length; i++) {
        // compare each to the regular expression, if it matches then it needs to be replaced with an html entity
        str[i] = str[i].replace(/[&<>"']/g, (a) => entify(a) );
    }
    str = str.join('');
    console.log(str);
    return str;
}

 convertHTML("Hello, World! It's  \">_<\"  great to be here & live.");
 // => "Hello, World! It&​apos;s  &​quot;&​gt;_&​lt;&​quot;  great to be here &​amp; live."

Upvotes: 2

Toto
Toto

Reputation: 91385

Call entify as a callback:

function convertHTML(str) {

    // html entity switch block
    function entify(char){
       // alert(char);
        switch (char) {
            case '&':
                return '&​amp;';
            case '<':
                return '&​lt;';
            case '>':
                return '&​gt;';
            case '"':
                return '&​quot;';
            case '\'':
                return '&​apos;';
        }
    }


    // convert string into an array
    str = str.split('');
    // loop through the array
    for (var i = 0; i < str.length; i++) {
        // compare each to the regular expression, if it matches then it needs to be replaced with an html entity
        //console.log(str[i]);
        str[i] = str[i].replace(/[&<>"']/g, function(m) {return entify(m);});
        //                          here ___^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    }
    str = str.join('');
    return str;
}

console.log(convertHTML(">"));

Upvotes: 2

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