循环填充Javascript-Object键/值吗？

Question

I want to do something like this:

let obj = [];

for(let i=0;i<4;i++) {

// doing some stuff here ...
// and then, finally:

obj[i].words = wordsOfSentence;
}

However this gives me an error.

Cannot set property 'words' of undefined

For now, I solved it like this:

let obj = [{}, {}, {}, {}];

for(let i=0;i<4;i++) {

// doing some stuff here ...
// and then, finally:

obj[i].words = wordsOfSentence;
}

...but this means I have to always push an empty object into the array beforehand? Whats the standard / an elegant solution here?

Answer 1

You must have to create a blank JSON object, before store any key-value pair and then you will push a JSON object in array.

let objects = [];
for (let i = 0; i < 4; i++) {
    objects[i] = {};
    objects[i].words = 'wordsOfSentence';  
    objects.push(objects[i]);  

}

console.log(objects);

Answer 2

Create the object and then add it to the array:

let obj = [];

for(let i=0;i<4;i++) {

// doing some stuff here ...
// and then, finally:
const newObj = { words: wordsOfSentence }
obj[i] = newObj;
}

Answer 3

You can use if statement

if( obj[i] ){
  obj[i].words = wordsOfSentence;
}

Or you can assign a default value before accessing

obj[i] = obj[i] || {}

Answer 4

You can simply push a new object in each iteration.

let objects = [];

for (let i = 0; i < 4; i++) {
    objects.push({words: wordsOfSentence});
}

Answer 5

let _obj = {};
_obj.words = [];
for (let i = 0; i < 4; i++) {    
    _obj.words.push('WordsOfSentense');
}
console.log(_obj);

This should help.