Operators and Loops

Comparision Operators

You can evaluate a situation by comparing one value in the script to what you expect it might be. The result will be a boolean.

• Boolean: true or false
• ==: is equal to, compares two values to see if they are the same
• !=: is not equal, compares two values to see if they are not the same
• ===: strict equal, compares two values to check that both the data type and the value are the same
• !==: strict not equal, compares two values to check that both the data type and value are not the same
• >: greater than, checks if the number on the left is greater than the number on the right
• <: less that, checks if the number on the left is less than the number on the right
• >=: greater than or equal to, checks if the number on the left is greater than or equal to the one on the right
• <=: less than or equal to, checks if the number on the left is less than or equal to the one on the right
• &&: logical and, tests more than one condition
• !: logical not, takes a single Boolean value and inverts it/reverses the state of an expression
• ||: logical or, tests atleast one condition

Loops

Loops check a condition. If it returns true, a code block will run. Then the condition will be checked again, & if it still returns true, the code block will run again. It will repeat until the condition returns false.

• For loop: if you need to run code a specific number of times
• While loop: if you do not know how many times the code should be run
• Do while loop: it will always run the statements inside the curly braces at once, even if the condition equals false

Using While Loops

• += operator: used to add content to the message variable. Works as shorthand for writing msg = msg + ‘new msg’