使用forEach的最大數字循環數組（）

Question

我想使用forEach Javascript方法拉數組的最大數目。這是我迄今爲止的，但我知道這是不正確的。

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

Answer 1

這將工作

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

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

console.log(largest); 

，但爲什麼你會甚至做呢？爲什麼不使用Math max？

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

Answer 2

如果你把console.log(largest); forEach循環之外，它會打印數組中數量最多。

Answer 3

要覆蓋數組中的負數，可以安全地將largest作爲數組中的第一個元素。

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

Answer 4

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.');