How to search a string for the most common character or word in JavaScript

user_17497724 0
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I have a question that asked me to:

Clean the following text and find the most frequent word: "const sentence = '%I $am@% a %tea@cher%, &and& I lo%#ve %te@a@ching%;. The@re $is no@th@ing; &as& mo@re rewarding as educa@ting &and& @emp%o@weri@ng peo@ple. ;I found tea@ching m%o@re interesting tha@n any ot#her %jo@bs. %Do@es thi%s mo@tiv#ate yo@u to be a tea@cher!? %Th#is 30#Days&OfJavaScript &is al@so $the $resu@lt of &love& of tea&ching'"

I used regEx to clean the string like this:

const sentence = '%I $am@% a %tea@cher%, &and& I lo%#ve %te@a@ching%;. The@re $is no@th@ing; && mo@re rewarding than educa@ting &and& @emp%o@weri@ng peo@ple. ;I find tea@ching m%o@re interesting tha@n any ot#her %jo@bs. %Do@es thi%s mo@tiv#ate yo@u to be a tea@cher!? %Th#is 30#Days&OfJavaScript &is al@so $the $resu@lt of &love& of tea&ching';
const sentReg = /\W(?<!1)/g;
let sent = sentence.replace(/ /g, "1");

let finalSent = sent.replace(sentReg, ""), finalfinalSent = finalSent.replace(/1/g, " ");

I realized I don't know how to (or there might not be a way to) use the match() function to search a string by word, so I tried splitting it up into an array like:

let senArr = finalfinalSent.split(" "), wordOccur = [];

for (const x of senArr) {
    var re = new RegExp(x, "g");
    var y = finalfinalSent.match(re);

    wordOccur = wordOccur.concat([y.length]);
};

... and now I'm stuck because I don't know how to search an array in JavaScript, only in Python, and I feel the way to search through a string would be much easier than this. I would appreciate some pointers.

arrays javascript string
1 Answers

I wouldn't change the spaces to "1". Instead use a regex that will not remove spaces while cleaning.

Then you can call match on the cleaned string, and use reduce to start counting words and maintain a reference to the most frequent one:

const sentence = '%I $am@% a %tea@cher%, &and& I lo%#ve %te@a@ching%;. The@re $is no@th@ing; && mo@re rewarding than educa@ting &and& @emp%o@weri@ng peo@ple. ;I find tea@ching m%o@re interesting tha@n any ot#her %jo@bs. %Do@es thi%s mo@tiv#ate yo@u to be a tea@cher!? %Th#is 30#Days&OfJavaScript &is al@so $the $resu@lt of &love& of tea&ching';

let word = sentence.replace(/[^\w\s]/g, "")
            .match(/\w+/g)
            .reduce((acc, word) => {
                acc[word] = (acc[word] || 0) + 1;
                if (!(acc[word] < acc[acc.$])) acc.$ = word;
                return acc;
            }, {}).$;
            
console.log(word);

Observe that acc will be a "dictionary" of words, where the corresponding values are the counts. A special $ entry is created in that same dictionary, which will hold the most frequent word.

If there is more than one word that has the maximum frequency, and you want to get all of these words, not just one, then return an array instead of a string:

const sentence = '%I $am@% a %tea@cher%, &and& I lo%#ve %te@a@ching%;. The@re $is no@th@ing; && mo@re rewarding than educa@ting &and& @emp%o@weri@ng peo@ple. ;I find tea@ching m%o@re interesting tha@n any ot#her %jo@bs. %Do@es thi%s mo@tiv#ate yo@u to be a tea@cher!? %Th#is 30#Days&OfJavaScript &is al@so $the $resu@lt of &love& of tea&ching';

let word = sentence.replace(/[^\w\s]/g, "")
            .match(/\w+/g)
            .reduce((acc, word) => {
                acc[word] = (acc[word] || 0) + 1;
                if (!(acc[word] <= acc[acc.$])) acc.$ = [word];
                else if (acc[word] === acc[acc.$]) acc.$.push(word);
                return acc;
            }, {}).$;
            
console.log(word);

user_54598390
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