copyWithin

Author: than-dev

@types/copyWithin.d.ts

@@ -0,0 +1,6 @@
+/**
+ * @param {number} target
+ * @param {number} start
+ * @param {number | undefined } end
+ */
+export function copyWithin(target: number, start: number, end: number | undefined): void;

functions/concat.js

@@ -15,7 +15,7 @@ function concat(...valuesToConcat) {
         if(value.length === 0) continue
 
 
-        if (value[0]) {
+        if (Array.isArray(value)) {
             for (subValue of value) {
                 newArray.push(subValue)
             }

functions/copyWithin.js

@@ -0,0 +1,160 @@
+Array.prototype.copyWithin = copyWithin
+
+/**
+ * @param {number} target // is where it will be trade by copied value
+ * @param {number} start // position that will start to copy items
+ * @param {number | undefined } end // position that will end to copy items
+ */
+function copyWithin(target, start = 0, end = this.length) {
+    if (target > this.length - 1 || this.length - target < 0) {
+        throw new Error('Target value is invalid')
+    }
+    
+    const array = this
+    let copiedValues = []
+
+    // Test Passed ><><><><
+    if (start >= 0 && end >= 0) {
+        if (start === end) return array
+        
+        if (start > end) {
+             for (let i = end + 1; i <= start; i++) {
+                copiedValues.push(array[i])
+            }
+        }
+
+        if (start < end) {
+            for (let i = start; i < end; i++) {
+                copiedValues.push(array[i])
+            }
+        }
+    }
+
+    if (start < 0 && end < 0) {
+        if (start === end) return array
+        
+        if (start > end) {
+            for (let i = array.length + end; i < array.length + start; i++) {
+                copiedValues.push(array[i])
+            } 
+        }
+        
+        if (start < end) {
+            for (let i = array.length + start; i <=  array.length + end - 1; i++) {
+                copiedValues.push(array[i])
+            }
+        }
+    }
+
+    if (start < 0 && end >= 0) {
+        if (end >= array.length || array.length + start < 0) return array
+        if (array.length + start === end) return array
+
+        if (array.length + start > end) {
+            for (let i = end + 1; i <= array.length + start; i++) {
+                copiedValues.push(array[i])
+            }
+        }
+
+        if (array.length + start < end) {
+            for (let i = array.length + start; i <= end - 1; i++) {
+                copiedValues.push(array[i])
+            }
+        }
+    }
+    
+    if (start >= 0 && end < 0) {
+        if (start >= array.length || array.length + end < 0) return array
+        if (array.length + end === start) return array
+        
+        if (array.length + end === start) {
+            copiedValues.push(array[start])
+        }
+
+        if (array.length + end > start) {
+            for (let i = start; i < array.length + end; i++) {
+                copiedValues.push(array[i])
+            }
+        }
+
+        if (array.length + end < start) {
+            for (let i = array.length + end + 1; i <= start; i++) {
+                copiedValues.push(array[i])
+            }
+        }
+    }
+
+    if (target === 0) {
+        let counter = copiedValues.length
+
+        while(counter > 0) {
+            counter--
+            array.shift()
+        }
+        for (let i = copiedValues.length - 1; i > -1; i--) {
+            array.unshift(copiedValues[i])
+        }
+
+        return array
+    }
+
+    if (target === array.length - 1 || target === -1) {
+        array.pop()
+        array.push(copiedValues[0])
+
+        return array
+    }
+
+    if (target !== 0 && array.length + target >= 0 && target !== array.length - 1 && target !== -1) {
+        if (target < 0) {
+            let targetPosition = array.length
+
+            while (target < 0) {
+                target++
+                targetPosition--
+            }
+            
+            const removedItems = array.splice(targetPosition, copiedValues.length)
+
+            if (array.length + removedItems.length - targetPosition > copiedValues.length) {
+                let itemsToInsert = [];
+                copiedValues.forEach(el => {
+                    if (itemsToInsert.length === removedItems.length) return
+                    itemsToInsert.push(el)
+                })
+                array.splice(targetPosition, undefined, ...itemsToInsert)
+            }
+
+            if (array.length + removedItems.length - targetPosition < copiedValues.length) {
+                while (array.length + removedItems.length - targetPosition < copiedValues.length) {
+                    copiedValues.pop()
+                }
+                array.splice(targetPosition, undefined, ...copiedValues)
+            }
+        }
+
+        if (target > 0) {
+            const removedItems = array.splice(target, copiedValues.length)
+            
+            if (array.length + removedItems.length + target > copiedValues.length) {
+                let itemsToInsert = [];
+                copiedValues.forEach(el => {
+                    if (itemsToInsert.length === removedItems.length) return
+                    itemsToInsert.push(el)
+                })
+                array.splice(target, undefined, ...itemsToInsert)
+            }
+
+            if (array.length + removedItems.length + target < copiedValues.length) {
+                while (array.length + removedItems.length + target < copiedValues.length) {
+                    copiedValues.pop()
+                }
+                array.splice(target, undefined, ...copiedValues)
+            }
+        }
+
+        return array
+    }
+}
+
+module.exports = { copyWithin }