Angular 2：Array Concat方法不起作用

Question

在下面的函数中，我试图通过连接tmp数组的值来构建filteredProducts数组。 tmp数组包含元素，但在连接之后，filteredProducts数组为空。

假设布尔变量refineCriteria.bosch为真;

filterProducts(refineCriteria: Refine) {
this.filteredProducts = [];
let tmp = [];

let filtered = false;

if(refineCriteria.bosch) {
  tmp = this.products.filter(product => product.brand == "Bosch");
  this.filteredProducts.concat(tmp);
  filtered = true;      

  console.log("tmp = " + tmp);
  console.log("this.filteredProducts = " + this.filteredProducts);

}


if(!filtered) {
  this.filteredProducts = this.products;
}

console.log("filteredProducts = " + this.filteredProducts); 

this.filteredProductsEvent.emit(this.filteredProducts);
}