JSFiddle - React, Tailwind, and code Playground

JavaScript

obj = {
    prop1: 'val',
    prop2: 'val2'
}

function hasOwnPropValue(obj, val) {
    for (var keys in obj) if (obj[keys] === val) return true;
    return false;
}

alert(hasOwnPropValue(obj, 'val2'));