const array = [ 'fatfish', 'hello', 'world', 24 ]
console.log(array.indexOf('fatfish')) // 0
console.log(array.indexOf('medium')) // -1



const array = [
  {
    name: 'fatfish'
  },
  {
    name: 'hello'
  },
  {
    name: 'world'
  },
]
const index = array.findIndex((it) => it.name === 'fatfish') // 0