[Updated] JavaScript(web2)_9

[Green-JEONG]

1. Grammar of Conditional Statements (조건문 문법)

(1) if statement:

• If statement is followed by the boolean data.
• True: The value before 'else' is returned.
• False: The value after 'else' is returned.

2. Utilization of Conditional Statements (조건문 활용)

• 'javascript element get value' (1) Search in Console.

  > document.querySelector('#night_day')
  < <input id="night_day" type="button" value="night" onclick="
  if () {
    document.querySelector('body').style.backgroundColor = 'black';
    document.querySelector('body').style.color = 'white';
  } else {
    document.querySelector('body').style.backgroundColor = 'white';
    document.querySelector('body').style.color = 'black';
  }
  ">

> document.querySelector('#night_day').value
< 'night'

• We can get the value of tag with an Id value of 'night_day'

[Green-JEONG]

It took a total of 10 minutes.