How can I check if there are others inside one string? [duplicate]

You can use the indexOf method to check if one of these words is located in the last string.

let palavras = ".org, .edu, .edu";

console.log(palavras.indexOf(".org"));

In this example the return will be 0 the current position of the word .org ; if the reference does not exist indexOf will return -1

To pass to a function just check the return

let palavras = ".org, .edu, .edu";

function verificaOcorrencias(sequencia, palavra){
    if(sequencia.indexOf(palavra) !== -1){
        return true;
    }else{
        return false;
    }
}

console.log(verificaOcorrencias(palavras, ".org")); //true
console.log(verificaOcorrencias(palavras, "algo")); //false

To do this check you can use the indexOf method of String

This method is case sensitive (so we changed the string and search key to uppercase), returns -1 when it does not find the key to search for otherwise returns the first position where the key was found.

link

const url = "omeusite.edu";

const chave = "edu";

if (url.toUpperCase().indexOf(chave.toUpperCase()) > -1) {
  alert("A chave foi encontrada!")
}