[英]Filter by object key inside array
使用MDN提供的示例(在該頁面下半部分的“在數組中搜索”示例中) ,如何更改此屬性,以能夠通過對象鍵按數組內部對象進行過濾? 現在出現錯誤: TypeError: el.toLowerCase is not a function
。
var searchTerm = "lotty"; var arr = [ {user: "William", message:"meet me in the nanoscale library"}, {user: "Lotty", message:"sounds like a plan"} ]; function filterItems(query) { return arr.filter(function(el) { return el.toLowerCase().indexOf(query.toLowerCase()) > -1; }) } var filteredArr = filterItems(searchTerm); console.log(filteredArr);
el
是要迭代的對象,而不是user
字符串,因此el.toLowerCase()
不起作用。 根據需要,首先將el
分解為user
:
var newUser = "lotty"; var arr = [ {user: "William", message:"meet me in the nanoscale library"}, {user: "Lotty", message:"sounds like a plan"} ]; function filterItems(query) { return arr.filter(function({ user }) { return user.toLowerCase().indexOf(query.toLowerCase()) > -1; }) } var filteredArr = filterItems(newUser); console.log(filteredArr);
或者,更簡潔地說,使用現代語法和.includes
:
var newUser = "lotty"; var arr = [ {user: "William", message:"meet me in the nanoscale library"}, {user: "Lotty", message:"sounds like a plan"} ]; const filterItems = query => arr.filter( ({ user }) => user.toLowerCase().includes(query.toLowerCase()) ); var filteredArr = filterItems(newUser); console.log(filteredArr);
SomePerformance的答案非常好。 但是,如果要使用分解,則必須確保對象具有user
密鑰。 像這樣: user&&user.toLowerCase().includes(query.toLowerCase())
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