Rest operator: with destructuring

Rest parameters with destructuring

must be last

const [...all, last] = [1, 2, 3, 4]; assert.deepEqual(all, [1, 2, 3, 4]);

assign rest of an array to a variable

const [...all] = [1, 2, 3, 4]; assert.deepEqual(all, [2, 3, 4]);

concat differently

const theEnd = [3, 4]; const allInOne = [1, 2, ...[theEnd]]; assert.deepEqual(allInOne, [1, 2, 3, 4]);

apply made simple, even for constructors

const theDate = [2015, 1, 1]; const date = new Date(theDate); assert.deepEqual(date, new Date(2015, 1, 1));

Related Katas

Unary Operators

• All unary operators
• Unary "+" operator
• Unary "+" operator in depth

Bitwise Shift Operators

• Left Shift "<<"
• Right Shift ">>"
• All bitwise shift operators

Rest operator

• as parameter
• with destructuring

Spread operator

• with arrays
• with strings

Difficulty Level

INTERMEDIATE

First Published

8 April 2015

Stats

4 tests to solve