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JavaScript: Get ISO-8601 numeric representation of the day of the week

JavaScript Datetime: Exercise-22 with Solution

Write a JavaScript function to get ISO-8601 numeric representation of the day of the week (1 (for Monday) to 7 (for Sunday)).

Test Data :
dt = new Date();
console.log(ISO_numeric_date(dt));
4
dt = new Date(2015, 10, 1);
console.log(ISO_numeric_date(dt));
7

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript function to get ISO-8601 numeric representation of the day of the week (1 (for Monday) to 7 (for Sunday))</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function ISO_numeric_date(dt)
{
  return (dt.getDay() === 0 ? 7 : dt.getDay()); 
}

dt = new Date();
console.log(ISO_numeric_date(dt));

dt = new Date(2015, 10, 1);
console.log(ISO_numeric_date(dt));

Sample Output:

3
7

Flowchart:

Flowchart: JavaScript- Get ISO-8601 numeric representation of the day of the week

Live Demo:

See the Pen JavaScript - Get ISO-8601 numeric representation of the day of the week-date-ex-22 by w3resource (@w3resource) on CodePen.


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Previous: Write a JavaScript function to get a full textual representation of the day of the week (Sunday through Saturday).
Next: Write a JavaScript function to get English ordinal suffix for the day of the month, 2 characters (st, nd, rd or th.).

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JavaScript: Tips of the Day

Log the values that are commented out after the console.log statement

function* startGame() {
  const answer = yield 'Do you love JavaScript?';
  if (answer !== 'Yes') {
    return "Oh wow... Guess we're gone here";
  }
  return 'JavaScript loves you back ?';
}

const game = startGame();
console.log(/* 1 */); // Do you love JavaScript?
console.log(/* 2 */); // JavaScript loves you back ?

A generator function "pauses" its execution when it sees the yield keyword. First, we have to let the function yield the string "Do you love JavaScript?", which can be done by calling game.next().value.
Every line is executed, until it finds the first yield keyword. There is a yield keyword on the first line within the function: the execution stops with the first yield! This means that the variable answer is not defined yet!
When we call game.next("Yes").value, the previous yield is replaced with the value of the parameters passed to the next() function, "Yes" in this case. The value of the variable answer is now equal to "Yes". The condition of the if-statement returns false, and JavaScript loves you back ? gets logged.

Ref: https://bit.ly/3jFRBje