FunctionalProgramming/JavaScript/2-condition.js at master · HowProgrammingWorks/FunctionalProgramming · GitHub

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'use strict';

// Declarative Style & Pure Functions

// Conditional expression instead of Conditional statement

const person = {

name: 'Marcus Aurelius',

born: 121,

city: 'Roma',

};

// Imperative

// Step-by-step instructions, mutable variables

{

let output = `${person.born} `;

if (person.born < 0) {

output += 'BC';

} else {

output += 'AD';

}

output = `${person.name} was born in ${output}`;

console.dir(output);

}

// Functional

// Declarative expressions, pure functions

{

const era = (year) => (year < 0 ? 'BC' : 'AD');

const formatBirthYear = (year) => `${year} ${era(year)}`;

const formatPersonInfo = (name, born) =>

`${name} was born in ${formatBirthYear(born)}`;

const output = formatPersonInfo(person.name, person.born);

console.dir(output);

}

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