问题描述
Given an array nums, write a function to move all 0’s to the end of it while maintaining the relative order of the non-zero elements.
For example, given nums = [0, 1, 0, 3, 12], after calling your function, nums should be [1, 3, 12, 0, 0].
思路1：先找出所有的0并将0保存在一个新的数组里，同时删除原数组中的0。最后将新数组拼接到原数组后面

/**
 * @param {number[]} nums
 * @return {void} Do not return anything, modify nums in-place instead.
 */
var moveZeroes = function(nums) {   
    var arr = new Array();
    for( var i = 0; i < nums.length; i++){  
        if(nums[i] === 0){
            arr.push(nums[i]);
            nums.splice(i,1);
            i--;
        }
    }
    for(var j = 0; j < arr.length; j++) {
            nums.push(arr[j]);
        }  
};

思路2：通过改变数组的下标来保存不为0 的值，同时记得将不为0的元素替换为0,。

var moveZeroes = function(nums) {
    var c1=0;
    for(var i=0;i<nums.length;i++){
        if(nums[i]!==0){
            if(c1!=i){
                nums[c1]=nums[i];
                nums[i]=0;
            }
            c1++;
        }
    }
};