Question

我有此列表：

list1 = [['phone1','123'],['phone2','125'],...]

我想检查变量x是否在列表中例如，当x =='123'时，它不会被推送到list1。

我尝试了这段代码，但是没有得到它：

const phone = this.eForm.value['phone'];
const name= this.eForm.value['name'];
for (let i = 0; i < list1.length; i++) {
      if (list1[i][1] == phone) {
        list1.push([name, phone]);
      }
    }

Answer 1

这将搜索您记录的2D数组，并允许您使用find()进行搜索。选中docs here。

let list1 = [
  ['phone1', '123'],
  ['phone2', '125']
];

let phone = '123';
let phoneName = 'phone3';

//Find() method will search each item of the array and return the result
let foundResult = list1.find((listItem) => {
  return listItem[1] === phone
});

//Find() method will search each item of the array and return the result.  This one will not find a match.
let notFoundResult = list1.find((listItem) => {
  return listItem[1] === '555-555-5555'
});

console.log(`First Output: ${(foundResult) ? 'Found Something!' : 'Nope'}`);
console.log(`Second Output: ${ (notFoundResult) ? 'Found Something!' : 'Nope'}`);

Answer 2

let list1 = [['phone1','123'],['phone2','125']];

const phone = 'phone3';

if(list1.reduce((n, element) => { return n + (element[0] == phone) }, 0) > 0)
{
console.log("phone3 exists in list1");
}
else
{
console.log("phone3 is not anywhere in list1");
}

reduce函数返回的值表示list1数组中出现“ phone3”的次数。

因此，如果大于0，则存在“ phone3”。

检查列表3中的元素是否离子

2 个答案: