Question

我试图使用forEach Javascript方法拉出最大数量的数组。这是我到目前为止所做的，但我知道这不正确。

＆＃13;

var arr = [2,3,4];
var largest = 0;
 
arr.forEach(function(elem){
  if(largest < elem) 
  largest = elem;
  console.log(largest);
});

＆＃13;

Answer 1

这将有效

var arr = [2,3,4];
var largest = 0;

arr.forEach(function(elem){
  if(largest < elem) 
  largest = elem;
});

console.log(largest);

但你为什么要这样做呢？为什么不使用Math max？

var largest = Math.max.apply(Math, arr);

Answer 2

如果将console.log(largest);放在forEach循环之外，它将打印数组中最大的数字。

Answer 3

要覆盖数组中的负数，可以安全地将largest指定为数组中的第一个元素。

var arr = [2,3,4];
var largest = arr[0];
 
arr.forEach(function(elem){
  if(largest < elem) 
  largest = elem;
});
console.log(largest);

Answer 4

您可以简单地使用传播运算符：

var arr = [2,3,4];
var largest = Math.max(...arr); 
console.log(largest);

Answer 5

var
    a = [2,3,4,2,1,9],
    largest = 0;

a.forEach(function(value){
    console.log('current array element value: ' + value + '.  Is it larger than the largest?', (largest > value));
    if (largest < value) largest = value;
    console.log('largest value now is: ', largest);
});
console.log('largest is changed here, because it was not redefined inside the function of the forEach method: ', largest, '.\n But it was defined within its context.');

Answer 6

function greatest(array) {
    if(array == undefined){
        console.log('There are no elements in array.');
    }

    const max = array.reduce(function(first, next){
        return first > next ? first : next; 
    });

    console.log(`Maximum element is ${max}`);
}

使用forEach（）循环数组的最大数字

6 个答案: