How to find a word in Javascript array?

Question

My question is, how can I find all array indexes by a word ?

[
{name: "Jeff Crawford", tel: "57285"},
{name: "Jeff Maier", tel: "52141"},
{name: "Tim Maier", tel: "73246"}
]

If I search for "Jeff", I want to get:

[
{name: "Jeff Crawford", tel: "57285"},
{name: "Jeff Maier", tel: "52141"},
]

• Krishna Prashatt: You have anything that you tried?
• 31piy: You want only indices or the elements?
• mplungjan: Please visit the help center, take the tour to see what and How to Ask. Do some research, search for related topics on SO; if you get stuck, post a minimal reproducible example of your attempt, noting input and expected output.

Answer 1

To make it more versatile, you could take a function which takes an array of objects, the wanted key and the search string, wich is later used as lower case string.

function find(array, key, value) {
 value = value.toLowerCase();
 return array.filter(o => o[key].toLowerCase().includes(value));
}
var array = [{ name: "Jeff Crawford", tel: "57285" }, { name: "Jeff Maier", tel: "52141" }, { name: "Tim Maier", tel: "73246" }]
console.log(find(array, 'name', 'Jeff'));

Answer 2

Use .filter:

const input=[{name:"Jeff Crawford",tel:"57285"},{name:"Jeff Maier",tel:"52141"},{name:"Tim Maier",tel:"73246"}]
const filtered = input.filter(({ name }) => name.startsWith('Jeff'));
console.log(filtered);

If you want to check to see if "Jeff" is anywhere rather than only at the beginning, use .includes instead:

const input=[{name:"Jeff Crawford",tel:"57285"},{name:"foo-Jeff Maier",tel:"52141"},{name:"Tim Maier",tel:"73246"}]
const filtered = input.filter(({ name }) => name.includes('Jeff'));
console.log(filtered);

These are ES6 features. For ES5, use indexOf instead:

var input=[{name:"Jeff Crawford",tel:"57285"},{name:"foo-Jeff Maier",tel:"52141"},{name:"Tim Maier",tel:"73246"}]
var filtered = input.filter(function(obj){
 return obj.name.indexOf('Jeff') !== -1;
});
console.log(filtered);

Answer 3

Use Array#map on the original array and return the indices. Then filter out the undefined values:

const data = [{name:"Jeff Crawford",tel:"57285"},{name:"Jeff Maier",tel:"52141"},{name:"Tim Maier",tel:"73246"}];
const indices = data.map((item, i) => {
 if (item.name.startsWith('Jeff')) {
 return i;
 }
 })
 .filter(item => item !== undefined);
console.log(indices);

Answer 4

Use array filter method along with indexOf. filter will return a new array of matched element. In side the filter callback function check for the name where the indexOf the keyword is not -1. That is the name should contain the keyword

var originalArray = [{
 name: "Jeff Crawford",
 tel: "57285"
 },
 {
 name: "Jeff Maier",
 tel: "52141"
 },
 {
 name: "Tim Maier",
 tel: "73246"
 }
]
function getMatchedElem(keyWord) {
 return originalArray.filter(function(item) {
 return item.name.indexOf(keyWord) !== -1
 })
}
console.log(getMatchedElem('Jeff'))