我目前是一名学习 Javascript 的学生,我的工作中出现了以下代码:
var currentInventory = [
{
name: 'Brunello Cucinelli',
shoes: [
{name: 'tasselled black low-top lace-up', price: 1000},
{name: 'tasselled green low-top lace-up', price: 1100},
{name: 'plain beige suede moccasin', price: 950},
{name: 'plain olive suede moccasin', price: 1050}
]
},
{
name: 'Gucci',
shoes: [
{name: 'red leather laced sneakers', price: 800},
{name: 'black leather laced sneakers', price: 900}
]
}
];
function filterBlackShoes(shoeList) {
return shoeList.filter(function(shoe){
return shoe.name.indexOf('black') !== -1;
})
}
function renderBlackShoesForDesigner(designer, shoeList) {
shoeList = filterBlackShoes(shoeList);
return shoeList.map(function(shoe){
return [designer, shoe.name, shoe.price].join(', ')
})
}
function renderFilteredGoodsStringForDesigner(designerObject) {
return renderBlackShoesForDesigner(designerObject.name,
designerObject.shoes).join('\n');
}
function renderInventory(inventory) {
return inventory.map(function(designerObject) {
return renderFilteredGoodsStringForDesigner(designerObject);
}).join('\n');
}
所以我明白了代码的作用,它过滤黑色鞋子并返回该信息。除了 !== -1 的作用外,我了解代码工作原理的所有方面。我会去找我的老师,但他们目前处于离线状态。有人可以向我解释一下它的重要性吗?
最佳答案
indexOf
在找不到项目时返回 -1
。 !==
是一个严格的不等于运算符。所以那里的声明试图说找到了该项目。
关于javascript - !== -1 有什么意义?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/45291775/