Category: JavaScript Answers

Sometimes, we want to convert string to datetime with JavaScript.

In this article, we’ll look at how to convert string to datetime with JavaScript.

How to convert string to datetime with JavaScript?

To convert string to datetime with JavaScript, we use the Date constructor.

For instance, we write

const s = "01-01-2022 00:03:44";
const d = new Date(s);
console.log(d);

to call the Date constructor with string to return a Date object converted from the string.

Conclusion

To convert string to datetime with JavaScript, we use the Date constructor.

Sometimes, we want to check if first letter of word is a capital letter with JavaScript.

In this article, we’ll look at how to check if first letter of word is a capital letter with JavaScript.

How to check if first letter of word is a capital letter with JavaScript?

To check if first letter of word is a capital letter with JavaScript, we use a regex.

For instance, we write

const word = "Someword";
console.log(/^[A-Z]/.test(word));

to call /^[A-Z]/.test with word to check if the first letter of word starts with a capital letter.

^ is the symbol for the beginning of the string.

[A-Z] is a pattern that matches upper case letters.

Conclusion

To check if first letter of word is a capital letter with JavaScript, we use a regex.

Sometimes, we want to generate sequence of numbers or characters in JavaScript.

In this article, we’ll look at how to generate sequence of numbers or characters in JavaScript.

How to generate sequence of numbers or characters in JavaScript?

To generate sequence of numbers or characters in JavaScript, we call the array fill method.

For instance, we write

const chars = Array(8).fill(1);

to call Array to create an array with 8 empty slots.

Then we call fill with 1 to fill all the empty slots with 1’s.

Conclusion

To generate sequence of numbers or characters in JavaScript, we call the array fill method.

Sometimes, we want to fix for each … in not working in Node.js and JavaScript.

In this article, we’ll look at how to fix for each … in not working in Node.js and JavaScript.

How to fix for each … in not working in Node.js and JavaScript?

To fix for each … in not working in Node.js and JavaScript, we use the array forEach method.

For instance, we write

array.forEach((item) => {
  //...
});

to call array.forEach with a callback.

And we get the item being looped through from item.

Conclusion

To fix for each … in not working in Node.js and JavaScript, we use the array forEach method.

Sometimes, we want to traverse through JavaScript object properties.

In this article, we’ll look at how to traverse through JavaScript object properties.

How to traverse through JavaScript object properties?

To traverse through JavaScript object properties, we use the for-of loop and the Object.entries property.

For instance, we write

const object1 = {
  a: "somestring",
  b: 42,
};

for (const [key, value] of Object.entries(object1)) {
  console.log(`${key}: ${value}`);
}

to call Object.entries to return an array with the key-value pair arrays in object1.

Then we use a for-of loop to get the key and value of each property.

Conclusion

To traverse through JavaScript object properties, we use the for-of loop and the Object.entries property.