what is a function expression code example

Example 1: function expression vs function declaration

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

Example 2: javascript function expression

const mul = function(x, y){
    return x * y;
}; //semicolon needs to be there as it is expression

console.log(mul(10, 20));