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"},
]

Answer 1

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 2

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'))

Answer 3

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 4

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);