JavaScript - convert json text to string variable

In this article, we would like to show you how to convert JSON text to string variables in JavaScript.

1. JSON.parse example

// ONLINE-RUNNER:browser;

function parseString(json) {
    var text = JSON.parse(json);

    if(typeof(text) == 'string') {
        return text;
    }

    throw new Error('Incorrect type!');
}

// Example:

var json = '"This is example text..."';
var text = parseString(json);

console.log(text);

2. Custom conversion method example

// ONLINE-RUNNER:browser;

var JsonUtils = new function() {
  var expression = /(\\*)"/g;

  function getContent(json) {
    if (json) {
      var limit = json.length - 1;

      if (json[0] == '"' && json[limit] == '"') {
        return json.substring(1, limit);
      }
    }

    return null;
  }

  this.parseString = function(json) {
    var content = getContent(json);

    if (content) {
      var result = content.replace(expression, function(value, escape) {
        if(escape.length % 2) {
          var result = '';

          for(var i = 1; i < escape.length; i += 2) {
            result += '\\';
          }

          return result + '"';
        }

        throw new Error('Incorrect json format!');
      });
    
      return result;
    }

    throw new Error('Incorrect json format!');
  }
};

// Example:

var json = '"Example SQL query: \\"SELECT * FROM `users`;\\""';
var text = JsonUtils.parseString(json);

console.log(text);

See also

1. JavaScript - deserialize json to object