I would like to know whats wrong with my code. As in the title descripted I would like to turn around the content of an array with a for loop to another array. I would like to use ES5 for this since I am not used to ES6+ yet.
Here is my code:
var arrayA = ["h","e","l","l","o"];
var arrayB = [];
function copyArray(oldArray, newArray) {
oldArray.forEach(function() {
var storeElement = oldArray.pop();
newArray.push(storeElement);
});
console.log(oldArray + " old array");
console.log(newArray + " new array");
}
copyArray(arrayA, arrayB);The result is:
"h,e,l,l old array" "o new array" "h,e,l old array" "o,l new array" "h,e old array" "o,l,l new array" "h,e FINAL old array" "o,l,l FINAL new array"
But it should be:
"" FINAL old array "o, l, l, e, h" FINAL new array.
What is going wrong?
Advertisement
Answer
Ok so Issue is your forEach which not running with oldArray length mean 5 times
Why this is happening? It is because you are poping out value withing forEach which change the length and data of forEach.
You can check by putting console.log(oldArray); in forEach.
var arrayA = ["h", "e", "l", "l", "o"];
var arrayB = [];
function copyArray(oldArray, newArray) {
var length = oldArray.length;
for (var i = 0; i < length; i++) {
var storeElement = oldArray.pop();
newArray.push(storeElement);
};
console.log(oldArray + " old array");
console.log(newArray + " new array");
}
copyArray(arrayA, arrayB);
var reverseArray = ["h", "e", "l", "l", "o"].reverse();
console.log("reverse array");
console.log(reverseArray);