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user13558
Asked: 2020-03-25 15:12:45 +0800 CST 2020-03-25 15:12:45 +0800 CST

Add borders to words in regular expressions

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I want to have a Javascript function that uses regular expressions to add things to the borders of certain words in a text.

Example, I want to replace this:

The swift Indian bat happily ate thistle and kiwi. The stork played the saxophone...

... for the following, knowing that the keywords are swift , thistle and kiwi :

The <b>fast</b> Indian bat happily ate <b>thistle<b> and <b>kiwi</b>. The stork played the saxophone...

javascript

1 Answers

  1. Best Answer

    For this we are going to use the Javascriptreplace del method String, which receives two parameters, one is the regular expression (pattern), and the other is the replacement expression.

    The first argument contains the keywords, they must be grouped using the form (?:lista), among other things, to save memory, and separated by the alternation operator | , in this case, swift, vermilion or kiwi. Also, to separate in complete words, it is used \bat the beginning and at the end of the word.

    It is as follows:

    /\b(?:veloz|cardillo|kiwi)\b/gi

    The second argument has a dollar sign followed by an American y (ampersand), is written $&, which returns all the text that was matched, and we can add the borders we want to the left and right, in this case, simulating a bold label <b>clave</b>.

    <b>$&</b>

    The action to replace is as follows.

    texto.replace(/\b(?:veloz|cardillo|kiwi)\b/gi,"<b>$&</b>")

    End code:

    function agregar_borde(texto,claves,izquierdo,derecho)
{
  var salida = claves.join("|")
  var expresión = new RegExp("\\b(?:"+salida+")\\b","gi")
  return texto.replace(expresión,izquierdo+"$&"+derecho)
}

var texto = "El veloz murciélago hindú comía feliz cardillo y kiwi."+
  " La cigüeña tocaba el saxofón..."

var palabras_claves = ["veloz","cardillo","kiwi"]
  
var izquierdo="<b>"
var derecho="</b>"

var resultado=agregar_borde(texto,palabras_claves,izquierdo,derecho)

document.write(texto)
document.write("<p/>")
document.write(resultado)

console.log(texto)
console.log(resultado)

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