merge sorted arrays

merge_sorted_arrays.js

function mergeArrays(leftArray, rightArray) {
  const result = [];
  
  let leftIndex = 0;
  let rightIndex = 0;
  const leftLen = leftArray.length;
  const rightLen = rightArray.length;
  
  while(result.length < leftLen + rightLen) {
    if (leftIndex < leftLen && (rightIndex === rightLen || leftArray[leftIndex] < rightArray[rightIndex])) {
      // 左侧数组中含有值 且 （右侧数组中无数据了 或 左侧对应的值小于右侧对应的值）
      result.push(leftArray[leftIndex])
      leftIndex ++;
    } else {
      result.push(rightArray[rightIndex])
      rightIndex ++;
    }
  }
  
  return result;
}