javascript tutorial - [Solved-5 Solutions] Check if a value is an object in javascript - javascript - java script - javascript array
Problem:
How to check if a value is an Object in JavaScript?
Solution 1:
Try using typeof(var) and/or var instanceof something.
Solution 2:
If typeof yourVariable === 'object', it's an object or null. If we want to exclude null, just make it yourVariable !== null && typeof yourVariable === 'object'.
Solution 3:
Object.prototype.toString.call(myVar) will return:
- "[object Object]" if myVar is an object
- "[object Array]" if myVar is an array
- etc.
Solution 4:
The official underscore.js uses this check to find out if something is really an object
// Is a given variable an object?
_.isObject = function(obj) {
return obj === Object(obj);
};
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Solution 5:
Little late... for "plain objects" (we mean, like {'x': 5, 'y': 7}) we have this little snippet:
function isPlainObject(o) {
return ((o === null) || Array.isArray(o) || typeof o == 'function') ?
false
:(typeof o == 'object');
}
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It generates the next output:
console.debug(isPlainObject(isPlainObject)); //function, false
console.debug(isPlainObject({'x': 6, 'y': 16})); //literal object, true
console.debug(isPlainObject(5)); //number, false
console.debug(isPlainObject(undefined)); //undefined, false
console.debug(isPlainObject(null)); //null, false
console.debug(isPlainObject('a')); //string, false
console.debug(isPlainObject([])); //array?, false
console.debug(isPlainObject(true)); //bool, false
console.debug(isPlainObject(false)); //bool, false
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It always works for me. If will return "true" only if the type of "o" is "object", but no null, or array, or function.