JavaScript Function

Function

function() {}

function greatWorls() {
  console.log("Hello world");
}
greatWorls();

Exercise

function getReminder() {
  console.log("Water the palnet");
}
getReminder();

function getInSpanish() {
  console.log("Buenas Tardes");
}
getInSpanish();

Parameters and Arguments

calculateArea(20, 10);

function calculateArea(width, height) {
  console.log(width * height);
}
    

Exrecise

sayThanks("Ashraf");
sayThanks("Siddik");
sayThanks("Jahangir");
sayThanks("Alam");

function sayThanks(name) {
  console.log("Thank you for your parchase " + name + "! We appreciate your business." );
}

Default Parameters

function animal(name = "Tiger") {
  console.log(`Animal is ${name}`);
  }

  animal("Cow"); // Outpur: Animal  is Tiger
  animal();  // Output: Animal is Tiger

Exercise

makeShoppingList();
function makeShoppingList(item1="Milk", item2="Bread", item3="Eggs") {
  console.log(`List: ${item1}, ${item2}, ${item3}`) 
}

makeShoppingList("Rice", "Alo", "Potato");
function makeShoppingList(item1="Milk", item2="Bread", item3="Eggs") {
  console.log(`List: ${item1}, ${item2}, ${item3}`) 
}

Return

without return

function rectangleArea(width, hight) {
      let area = width * hight
    }
    console.log(rectangleArea(5, 7)) // Prints: Undefined

with return

 function rectangleArea(width, hight) {
      let area = width * hight;
      return area;
      console.log("hello");
    }
    console.log(rectangleArea(5, 7));

Exercise

 const numOfMonitors = monitorCount(5, 4);
    console.log(numOfMonitors);

    function monitorCount(rows, columns) {
      return rows * columns;
    }

Helper Function

Function Expressions

const plantNeedsWater = function(day) {
        if(day === 'wednesday') {
          return true;
        } else {
          return false
        }
      }
      
      console.log(plantNeedsWater("Thuesday"));
      console.log(plantNeedsWater("wednesday"));

Arrow Expressions

const plantNeedsWater = (day) => {
  if(day === 'wednesday') {
    return true;
  } else {
    return false
  }
}

console.log(plantNeedsWater("Thuesday"));
console.log(plantNeedsWater("wednesday"));

Concise Body Arrow Funciton

const plantNeedsWater = (day) => day === 'wednesday'
      console.log(plantNeedsWater("Thuesday"));
      console.log(plantNeedsWater("wednesday"));