I have this snippet of code below and don't quite understand the output
function repeatStringNumTimes(str, num) {
if (num <0) {
return ""
} else {
return Array(num+1).join(str)
}
}
console.log(repeatStringNumTimes("abc", 3));
I would have expected the output to be "abcabcabc" though if I console.log(repeatStringNumTimes("abc", 3)) in JS Bin it produces "abcabc"?
If I specify Array(3) - Would it not concatenate the string 3 times? Why only 2 in this instance?
If I specify Array(3) - Would it not concatenate the string 3 times? Why only 2 in this instance?
console.log([1,2,3].join('abc'))
// outputs 1abc2abc3Note that 'abc' is the separator for the join between the 3 elements, and so it appears twice, not 3 times.
Therefore, if you create an empty array, it shows 'abc' twice, separating 3 empty strings:
console.log(Array(3).join('abc'))
// outputs abcabcAlso note that there is String.repeat()
console.log('abc'.repeat(3))
// outputs abcabcabclook when i run your code the right output appears so your code has no bugs, and when you specify Array(3) the output will be "abcabc" your code is working well
If you will have a look into the Array#join documentation, It will join the array items based on the passed separator in the join method. Ideally, It will not consider the join before the first and after the last element in an array.
console.log(Array(3)) // [undefined, undefined, undefined]
console.log([undefined, undefined, undefined].join('abc')); // 'abcabc'As you want to fill the array with the string, Correct method is Array#fill which changes all elements in an array to a static value, from a start index (default 0) to an end index (default array.length) and then join the elements from an array with the help of Array.join() method.
console.log(Array(3).fill('abc').join(''));
abcabcabc(so abc 3x times) - which is expected, because your passing in3