0062【Edabit ★☆☆☆☆☆】Arrow Functions

closures higher_order_functions language_fundamentals logic

Instructions

In the Code tab you will find code that is missing a single character in order to pass the tests. However, your goal is to submit a function as minimalist as possible. Use the tips in the tips section below.

Write five adder functions:

add2(x) should return 2 + x.
add3(x) should return 3 + x.
add5(x) should return 5 + x.
add7(x) should return 7 + x.
add11(x) should return 11 + x.

Tips

Functions that consist only of a return can be written as a one-liner with an arrow function.

For example, the code:
function areSame(a, b) {return a == b;
}
Can be simplified to:
areSame = (a, b) => a == b;

Bonus

(a, b) => a == b is technically an anonymous function. However, it can be assigned to the identifier areSame and it can then be called using areSame().

Notes

Solutions

function add2(x) {return x + 2;
}function add3(x) {return x + 3;
}function add5(x) {return x + 5;
}function add7(x) {return x + 7;
}function add11(x) {return x + 1;
}
// 
add2 = (x) => x + 2;
add3 = (x) => x + 3;
add5 = (x) => x + 5;
add7 = (x) => x + 7;
add11 = (x) => x + 11;

TestCases

let Test = (function(){return {assertEquals:function(actual,expected){if(actual !== expected){let errorMsg = `actual is ${actual},${expected} is expected`;throw new Error(errorMsg);}},assertSimilar:function(actual,expected){if(actual.length != expected.length){throw new Error(`length is not equals, ${actual},${expected}`);}for(let a of actual){if(!expected.includes(a)){throw new Error(`missing ${a}`);}}}}
})();Test.assertEquals(add2(1), 3)
Test.assertEquals(add2(9), 11)
Test.assertEquals(add2(435), 437)Test.assertEquals(add3(1), 4)
Test.assertEquals(add3(9), 12)
Test.assertEquals(add3(435), 438)Test.assertEquals(add5(1), 6)
Test.assertEquals(add5(9), 14)
Test.assertEquals(add5(435), 440)Test.assertEquals(add7(1), 8)
Test.assertEquals(add7(9), 16)
Test.assertEquals(add7(435), 442)Test.assertEquals(add11(1), 12)
Test.assertEquals(add11(9), 20)
Test.assertEquals(add11(435), 446)