Category: JavaScript Answers

Sometimes, we want to verify image URL with JavaScript.

In this article, we’ll look at how to verify image URL with JavaScript.

How to verify image URL with JavaScript?

To verify image URL with JavaScript, we can try to load the URL into an Image object.

For instance, we write

const doesImageExist = (url) =>
  new Promise((resolve) => {
    const img = new Image();

    img.src = url;
    img.onload = () => resolve(true);
    img.onerror = () => resolve(false);
  });

to define the doesImageExist function that returns a promise.

We define a promise with the Promise constructor called with a function that creates an Image object.

We set the src property to url to load the url into the img element.

And then we listen for success or error by setting the onload and onerror properties to functions respectively.

When onload is called, the url is a valid image URL so we call resolve with true.

If onerror is called, the url isn’t a valid image URL so we call resolve with false.

Conclusion

To verify image URL with JavaScript, we can try to load the URL into an Image object.

Sometimes, we want to find by text content with Cypress and JavaScript.

In this article, we’ll look at how to find by text content with Cypress and JavaScript.

How to find by text content with Cypress and JavaScript?

To find by text content with Cypress and JavaScript, we use the contains method.

For instance, we write

cy.get(".YOUR_BUTTON_CLASS").contains("Customer");

to call get to get the element with class YOUR_BUTTON_CLASS.

Then we call contains to find the element in the button that has text 'Customer'.

Conclusion

To find by text content with Cypress and JavaScript, we use the contains method.

Sometimes, we want to disable eslint rule max line length for paragraph in template of Vue.js.

In this article, we’ll look at how to disable eslint rule max line length for paragraph in template of Vue.js.

How to disable eslint rule max line length for paragraph in template of Vue.js?

To disable eslint rule max line length for paragraph in template of Vue.js, we can add a comment to disable the rule for one or more lines.

For instance, we write

<template>
  <!-- eslint-disable-next-line max-len -->
  <my-long-component>...</my-long-component>
</template>

to disable the line length eslint rule for the line right after the comment.

And we write

<template>
  <!-- eslint-disable max-len -->
  <my-long-component> ... </my-long-component>
  <!-- eslint-enable max-len -->
</template>

to disable the line length eslint rule for the line between the disable and enable comment.

Conclusion

To disable eslint rule max line length for paragraph in template of Vue.js, we can add a comment to disable the rule for one or more lines.

Sometimes, we want to make a POST request with Fetch API and JavaScript.

In this article, we’ll look at how to make a POST request with Fetch API and JavaScript.

How to make a POST request with Fetch API and JavaScript?

To make a POST request with Fetch API and JavaScript, we call fetch with the method option set to 'post'.

For instance, we write

const res = await fetch("http://example.com/api/endpoint/", {
  method: "post",
  headers: {
    Accept: "application/json",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    name,
    password,
  }),
});

to call fetch with the URL to make the request to and an object with some request options.

In the object, we set method to 'post' to make a post request.

We set headers to an object with the request headers keys and values.

And we set body to a JSON string with the request body.

Conclusion

To make a POST request with Fetch API and JavaScript, we call fetch with the method option set to 'post'.

Sometimes, we want to remove array element by value with JavaScript.

In this article, we’ll look at how to remove array element by value with JavaScript.

How to remove array element by value with JavaScript?

To remove array element by value with JavaScript, we use the indexOf method.

For instance, we write

const arr = ["orange", "red", "black", "white"];
const index = arr.indexOf("red");
if (index >= 0) {
  arr.splice(index, 1);
}

to call arr.indexOf with 'red' to get the index of 'red' in arr.

Then we call splice to remove 'red' by calling it with index and 1.

Conclusion

To remove array element by value with JavaScript, we use the indexOf method.