在Javascript中向数组添加元素

Question

I am posting this question after I have done some search over stackoverflow for similar question but not able to find one.

const x =  {country: 'Sweden'};
const y =  {{name: 'james',status:'Green'},
   { name: 'Dave', status: 'Yellow'}};

Expected Output:

const z = {{name: 'james',status:'Green', country: 'Sweden'},
   { name: 'Dave', status: 'Yellow', country: 'Sweden'}};

I used forEach loop and tried to .push() or .concat() to an element of the loop, but getting an error "concat is not a function" and "pushis not a function"

  y.forEach(function(element) {
    x = x.concat(element); 
    console.log(x);  
  });

Answer 1

constant y is wrong according to javascript. First of all, please make it an array like below.

const y =  [{name: 'james',status:'Green'},
            { name: 'Dave', status: 'Yellow'}];

const x =  {country: 'Sweden'};

Then,

y.forEach(function(element) {
   element.country  = x.country; 
   console.log(x);  
 });

Answer 2

You may use Object.assign() method:

const z = y.map(o => Object.assign(o, x));

Demo:

 const x = {country: 'Sweden'}; const y = [ {name: 'james',status:'Green'}, {name: 'Dave', status: 'Yellow'} ]; const z = y.map(o => Object.assign(o, x)); console.log(z); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

Alternatively you can use spread syntax:

const z = y.map(o => ({...o, ...x}));

Demo:

 const x = {country: 'Sweden'}; const y = [ {name: 'james',status:'Green'}, {name: 'Dave', status: 'Yellow'} ]; const z = y.map(o => ({...o, ...x})); console.log(z); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

References:

• Array.prototype.map()
• Object.assign()