Determine if an array in Javascript includes an object as its only element

Question

Determine if an array in Javascript includes an object as its only element

I'm looking to create a function that can determine whether an array contains only objects. Here's what I came up with:

function checkArrayForObjects(arr){
  return arr.join("").replace(/\[object Object\]/g, "") === "";
}

Here's an example of how you would use this function:

// true
checkArrayForObjects([
  {"name" : "Alice", "age" : 30},
  {"name" : "Bob", "age" : 25}
]);

// false
checkArrayForObjects([
  {"name" : "Alice", "age" : 30},
  "name=Bob;age=25"
]);

Is there a more efficient way to achieve this? Is relying on the literal "[object Object]" secure for checking purposes? I'd also prefer a solution without jQuery.

javascript arrays

Answer 1

Answer №1

While conceptually simpler and more streamlined, this code achieves the same result:

function checkIfArrayContainsObjectsOnly(arr) {
  return arr.every(function(el) {
    return Object.prototype.toString.call(el) === '[object Object]';
  });
}

Update:

Upon further consideration, it appears that this revised version would be more optimal as it will immediately return false upon encountering a non-object element in the array:

function checkIfArrayContainsObjectsOnly(arr) {
  return !arr.some(function(el) {
    return Object.prototype.toString.call(el) !== '[object Object]';
  });
}

Answer 2

While conceptually simpler and more streamlined, this code achieves the same result:

function checkIfArrayContainsObjectsOnly(arr) {
  return arr.every(function(el) {
    return Object.prototype.toString.call(el) === '[object Object]';
  });
}

Update:

Upon further consideration, it appears that this revised version would be more optimal as it will immediately return false upon encountering a non-object element in the array:

function checkIfArrayContainsObjectsOnly(arr) {
  return !arr.some(function(el) {
    return Object.prototype.toString.call(el) !== '[object Object]';
  });
}

Answer 3

Answer №2

One way to check for the type of an element is by using the typeof operator.

Here's an example:

// Example:

var itemsArray = [
    {"name" : "juan", "age" : 28},
    {"name" : "pedro", "age" : 25},
    "name=pedro,age=25"
]

var allObjectsCheck = itemsArray.every(function(item, index){ 

    if ((typeof item) === "object") { 
        return true;
    } else {
        return false;
    }
});

console.log(allObjectsCheck)   // Returns false because one element is not an object


// Another Example:

var itemsArray = [
    {"name" : "juan", "age" : 28},
    {"name" : "pedro", "age" : 25},
    {"name" : "name=pedro,age=25"}
]

var allObjectsCheck = itemsArray.every(function(item, index){ 

    if ((typeof item) === "object") { 
        return true;
    } else {
        return false;
    }
});

console.log(allObjectsCheck)   // Returns true as all elements are objects

Answer 4

One way to check for the type of an element is by using the typeof operator.

Here's an example:

// Example:

var itemsArray = [
    {"name" : "juan", "age" : 28},
    {"name" : "pedro", "age" : 25},
    "name=pedro,age=25"
]

var allObjectsCheck = itemsArray.every(function(item, index){ 

    if ((typeof item) === "object") { 
        return true;
    } else {
        return false;
    }
});

console.log(allObjectsCheck)   // Returns false because one element is not an object


// Another Example:

var itemsArray = [
    {"name" : "juan", "age" : 28},
    {"name" : "pedro", "age" : 25},
    {"name" : "name=pedro,age=25"}
]

var allObjectsCheck = itemsArray.every(function(item, index){ 

    if ((typeof item) === "object") { 
        return true;
    } else {
        return false;
    }
});

console.log(allObjectsCheck)   // Returns true as all elements are objects

Determine if an array in Javascript includes an object as its only element

Answer №1

Answer №2

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