JavaScript shift()函数移出数组第一个数据
// 举例
var ourArray = ["Stimpson", "J", ["cat"]];
removedFromOurArray = ourArray.shift();
// removedFromOurArray now equals "Stimpson" and ourArray now equals ["J", ["cat"]].
// Setup
var myArray = [["John", 23], ["dog", 3]];
// Only change code below this line.
var removedFromMyArray=myArray.shift();