What is the use of the javascript shift() method?

In JavaScript, the function of the shift() method is to delete the first element of the array, return the value of the first element, and then shift all the remaining elements forward by 1 bit to fill the head of the array. Gap; syntax "array.shift()".

The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.

The shift() method can delete the first element of the array, return the element, and then shift all remaining elements forward by 1 position to fill the vacancy at the head of the array. If the array is empty, shift() will do nothing and return undefined.

Syntax: array.shift()

Return value: The value of the original first element of the array (removed element), which can be of any type (because The array element can be a string, number, array, Boolean, or other object type).

Example:

var a = [1,2,3,4,5,6,7,8];  //定义数组
a.shift();
console.log(a);

##Attached is a classic programming game: There is a group of monkeys platooning Form a circle and number them sequentially according to 1, 2, 3,..., n. Then start counting from the 1st finger, and when you count to the mth one, kick it out of the circle, and then start counting from behind it. When you count to the mth one again, continue to kick it out, and so on, until only the mth one is left. Until the next monkey, that monkey is called the king. Programming is required to simulate this process, input m, n and output the final king number.

//n表示猴子个数，m表示提出位置
function f(m,n) {
    //将猴子编号并放入数组
    var arr = [];
    for (i = 1; i < n+1; i ++) {
        arr.push(i);
    }
    //当数组内只剩下一只猴子时跳出循环
    while (arr.length > 1) {
        for (var i = 0; i < m-1; i ++) {  //定义排队轮转的次数
            arr.push(arr.shift());  //队列操作，完成猴子的轮转
        }
        arr.shift();  //提出第m只猴子
    }
    return arr;  //返回包含最后一只猴子的数组
}
console.log(f(5,3));  //编号为4的猴子胜出

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javascript advanced tutorial]

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