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1- Comparison and Logical operators

You can evaluate a situation by comparing one value in the script to what you expect it might be. The result wil be a boolean: true or false.

• > greater than: Returns true if the left operand is greater than the right operand.

• >= greater than or equal to:Returns true if the left operand is greater than or equal to the right operand.

• < less than:Returns true if the left operand is less than the right operand.

• *<= less than or equal to:Returns true if the left operand is less than or equal to the right operand. *

Keep in mind that you must use “==”, not “=”, when testing if two primitive values are equal.

• equal to (==) :Returns true if the operands are equal.
• not equal to (!=) : Returns true if the operands are not equal.
• Strict equal (===) :Returns true if the operands are equal and of the same type.
• Strict not equal (!==) :Returns true if the operands are of the same type but not equal, or are of different type.

- Logical operators

Logical operators allow you to compare the results of more than one comparison operator.

• Logical AND (&&)
  • expr1 && expr2
  • Returns expr1 if it can be converted to false; otherwise, returns expr2. Thus, when used with Boolean values, && returns true if both operands are true; otherwise, returns false.

• Logical OR (

  )

  • expr1

    expr2

  • Returns expr1 if it can be converted to true; otherwise, returns expr2. Thus, when used with Boolean values,

    returns true if either operand is true; if both are false, returns false.

• Logical NOT (!)
  • !expr
  • Returns false if its single operand that can be converted to true; otherwise, returns true.

  The following code shows examples of the && (logical AND) operator: var a1 = true && true; // t && t returns true var a2 = true && false; // t && f returns false var a3 = false && true; // f && t returns false var a4 = false && (3 == 4); // f && f returns false var a5 = ‘Cat’ && ‘Dog’; // t && t returns Dog var a6 = false && ‘Cat’; // f && t returns false var a7 = ‘Cat’ && false; // t && f returns false

2- LOOPS

Loops are used in JavaScript to perform repeated tasks based on a condition. Conditions typically return true or false when analysed. A loop will continue running until the defined condition returns false.

The three most common types of loops are:

1- For

If you need to run code a speciific number of times , use a for loop. in a for loop , the condition is usually a counter which is used to tell how many times the loop should run INITIALIZATION , CONDITION, UPDATE

2- while

If you do not know how many times the code should run , you can use a while loop. Here the condition can be something other than counter, and the code will continue to loop foras long as the condition is true using while loops

3- do while

The do…while loop is very similar to the while loop, but hasone key difference: itwill always run the statements inside the curly braces at least once, even if the condition evaluates to false.

Learn more about loops