JS VALUE, TYPE, OPERATORS

JS VALUE, TYPE, OPERATORS

1. Value: number, string, Boolean, object, function, undefined

2. Special Nulber

   • Infinity & -Infinity = vo cuc
   • NaN
     • = not a number
     • Return when 0/0

3. String

   • "String" or 'String'
   • escaping the character
     • backslash (\) 4 special meaning
     • "This is \nmy first \"eng\" class"
     • Concatenate <-- "con" + "cat" + "enate"

4. Unary Operators

   • typeof
     • return string value naming the type of the value you give it
     • console.log(typeof 4.5); --> number

5. Boolean Values

   • Comparision
     • < is less than
     • > is greater than
     • <= less than or equal
     • >= greater than or equal
     • == equal
     • != not equal to
     • === equal value and type
     • !== not equal value, same type
   • Logical
     • || or
     • && and
     • ! not
     • (condition) ? true : flase

6. Undefined

   • Auto type conversion
     • Trong JS, tu xd type varible
     • EX: "sfd" +1 -> String, "5"-1 -> number, "five"*2->NaN