JSFiddle - React, Tailwind, and code Playground

JavaScript

var arr = [{
  name: "john",
  value: 20
}, {
  name: "kate",
  value: 30
}, {
  name: "tony",
  value: 40
}];

myValue = 20;

arr.splice(arr.map(el => el.value).indexOf(myValue), 1); 
document.write(JSON.stringify(arr));