javascript - ReactJS - What is the best way to push data in an array within an array? -

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i wanted push data inside object(orders). orders have array inside products, parts , prints. want push data in prints only. meaning have 2 buttons, 1st button push data of orders while 2nd button push portion of orders, prints. can see prints under orders. can suggest way on how can this?

below array of orders have. want push data orders.prints

          orders: [{             product: {               ptype: '',               name: '',               brand: '',               color: '',               files: []             },             parts: [],             prints: [{               name: '',               width: '',               height: '',               colors: ''             }],             breakdown: [{               size: '',               quantity: 0             }]           }]

got working adding value in orders set index. orders[0]

onaddprint = () => {     var newprints = this.state.orders;     newprints[0].prints.push({               name: 'test',               width: 'test',               height: 'test',               colors:              });      this.setstate({       orders: this.state.orders.splice(0, 1, newprints)     });   }

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