总结javascript中遍历数组的几种方法

本篇文章给大家总结了一些javascript遍历数组的几种方法。有一定的参考价值，有需要的朋友可以参考一下，希望对大家有所帮助。

有几种方法可以遍历数组，下面将逐个罗列！

while循环

let index = 0; const array = [1, 2, 3, 4, 5];  while (index < array.length) {     console.log(array[index]);     index++; }

for循环

const array = [1,2,3,4,5]; for(let index=0;index<array.length;index++){     console.log(array[index]); } for(let index in array){     console.log(array[index]); }

forEach

const array=[1,2,3,4,5]; array.forEach(function(current_value,index,array){     console.log(`At index ${index} in array ${array} the value is ${current_value}`) })

map

最后一个构造很有用，但是不会返回新数组，这对于你的特定情况可能是不希望的。map通过对每个元素应用一个函数然后返回新数组来解决此问题。

const array = [1,2,3,4,5]; const square = x =>Math.pow(x,2); const squares = array.map(square); console.log(`${array}`); console.log(`${squares}`)

reduce

reduce()方法对累加器和数组中的每个元素(从左到右)应用一个函数，以将其减小为单个值

const array = [1,2,3,4,5]; const sum = (x,y) => x + y;  const array_sum = array.reduce(sum,0); console.log(`the sum of arrray:${array} is ${array_sum}`);

filter

根据布尔函数过滤筛选数组中的元素

const array = [1,2,3,4,5]; const even = x => x%2 === 0; const even_array = array.filter(even); console.log(`even numbers in array ${array} : ${even_array}`);

every

得到了一个数组，想测试每个元素是否满足给定条件

const array = [1,2,3,4,5,8]; const under_six = x => x<6; if(array.every(under_six)){     console.log(`every elemnet in the array is less than 6`); } else{     console.log(`at least one element in the array was bigger than 6`); }

some

测试是否至少有一个元素与布尔函数匹配

const array = [2,4,5,6,8]; const over_five = x => x>5;  if(array.some(over_five)){     console.log(`at least one element bigger than 5 was found`); } else{     console.log(`no element bigger than 5 was found`); }

到此就结束啦，