function expression vs function declaration

JavaScript
const functionExpression = function(width, height) {
  return width * height;
};

console.log(functionExpression(3, 4));
// Result = 12

function functionDeclaration(width,height){
return width * height;
};

console.log(functionDeclaration(3,4));
//Result = 12
const getRectArea = function(width, height) {
  return width * height;
};

console.log(getRectArea(3, 4));
// expected output: 12
const plantNeedsWater = function(day){
  if (day === 'Wednesday'){
    return true;
  } else{
    return false;
  }
}

console.log(plantNeedsWater('Tuesday'))
Source

Also in JavaScript: