Author: John Au-Yeung

Sometimes, we want to get current URL from an iframe with JavaScript.

In this article, we’ll look at how to get current URL from an iframe with JavaScript.

How to get current URL from an iframe with JavaScript?

To get current URL from an iframe with JavaScript, we can use the contentWindow.location.href property.

For instance, we write

const url = document.getElementById("iframe_id").contentWindow.location.href;

to select the iframe with

document.getElementById("iframe_id")

Then we get the current URL of the iframe with the contentWindow.location.href property.

Conclusion

To get current URL from an iframe with JavaScript, we can use the contentWindow.location.href property.

Sometimes, we want to check if JavaScript object is JSON.

In this article, we’ll look at how to check if JavaScript object is JSON.

How to check if JavaScript object is JSON?

To check if JavaScript object is JSON, we can use the JSON.parse method.

For instance, we write

const isJson = (data) => {
  try {
    const testIfJson = JSON.parse(data);
    if (typeof testIfJson === "object") {
      return true;
    } else {
      return false;
    }
  } catch {
    return false;
  }
};

to call JSON.parse with data to parse the data string.

If its type is 'object', then it’s JSON is it’s not null.

Otherwise, it’s not JSON.

If JSON.parse can’t parse data, an error will be thrown and false is returned since it’s not JSON.

Conclusion

To check if JavaScript object is JSON, we can use the JSON.parse method.

Sometimes, we want to debug FormData.append("key", "value") is not working with JavaScript.

In this article, we’ll look at how to debug FormData.append("key", "value") is not working with JavaScript.

How to debug FormData.append("key", "value") is not working with JavaScript?

To debug FormData.append("key", "value") is not working with JavaScript, we can loop through the values with a loop.

For instance, we write

for (const data of formData) {
  console.log(data);
}

to loop through the entries of the formData FormData object with a for-of loop.

In it, we log the data value.

This works because a FormData object is an iterable object.

Conclusion

To debug FormData.append("key", "value") is not working with JavaScript, we can loop through the values with a loop.

Sometimes, we want to check if a value is not null and not empty string in JavaScript.

In this article, we’ll look at how to check if a value is not null and not empty string in JavaScript.

How to check if a value is not null and not empty string in JavaScript?

To check if a value is not null and not empty string in JavaScript, we can use the !== operator.

For instance, we write

if (data !== null && data !== "") {
  // ...
}

to check if data isn’t null and data isn’t an empty string with

data !== null && data !== ""

Conclusion

To check if a value is not null and not empty string in JavaScript, we can use the !== operator.