Javascript 打字稿：按值检查数组中是否存在对象
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Typescript : Check if object exist in array by value
提问by firasKoubaa
I have this data:
我有这个数据：
roles = [
{roleId: "69801", role: "ADMIN"}
{roleId: "69806", role: "SUPER_ADMIN"}
{roleId: "69805", role: "RB"}
{roleId: "69804", role: "PILOTE"}
{roleId: "69808", role: "VENDEUR"}
{roleId: "69807", role: "SUPER_RB"}
]
i have to filter my table to check if there is an object containing a specifie value of role .
我必须过滤我的表以检查是否有包含角色特定值的对象。
My function should look like this :
我的函数应该是这样的：
checkRoleExistence(role){
// if role exists on one of the objects return true
// else returne false
}
to use it i would do s.th like this :
要使用它，我会这样做：
let ifExists = this.checkRoleExistence("PILOTE") ;
I would like to use the "filter"function of Ecmascript.
我想使用Ecmascript的“过滤器”功能。
Suggestions ?
建议？
回答by Mihai Alexandru-Ionut
You can use somemethod and destructuring.
您可以使用somemethod 和destructuring。
let roles = [ {roleId: "69801", role: "ADMIN"}, {roleId: "69806", role: "SUPER_ADMIN"}, {roleId: "69805", role: "RB"}, {roleId: "69804", role: "PILOTE"}, {roleId: "69808", role: "VENDEUR"}, {roleId: "69807", role: "SUPER_RB"} ]
const checkRoleExistence = roleParam => roles.some( ({role}) => role == roleParam)
console.log(checkRoleExistence("ADMIN"));
console.log(checkRoleExistence("RA"));
console.log(checkRoleExistence("RB"));回答by Sujay
a little addition to all the answers given here. You can use find() to get value which matches your requirement.
对这里给出的所有答案的一点补充。您可以使用 find() 获取符合您要求的值。
const index = this.roles.findIndex(role=> role.name === 'ADMIN');
if (index >-1) {
const value= this.roles[index].roleId);
}
const index = this.roles.findIndex(role=> role.name === 'ADMIN');
if (index >-1) {
const value= this.roles[index].roleId);
}
this will give you roleId , where it matches your query
这会给你 roleId ，它匹配你的查询
回答by Lester
I got this solution for you: check this out
我为你找到了这个解决方案： 看看这个
export class RoleComponent implements OnInit {
roles: Role[] = [];
isRoleExist:boolean = false;
constructor() { }
ngOnInit() {
const data = this.getRoles();
this.roles = JSON.parse(data);
this.isRoleExist = this.checkRoleExistence('PILOTE');
console.log(this.isRoleExist);
}
checkRoleExistence(roleLabel: string):boolean {
return this.roles.some(r => r.roleLabel === roleLabel);
}
getRoles() {
return `[
{"roleId": "69801", "roleLabel": "ADMIN"},
{"roleId": "69806", "roleLabel": "SUPER_ADMIN"},
{"roleId": "69805", "roleLabel": "RB"},
{"roleId": "69804", "roleLabel": "PILOTE"},
{"roleId": "69808", "roleLabel": "VENDEUR"},
{"roleId": "69807", "roleLabel": "SUPER_RB"}
]`;
}
}
export class Role {
roleId: number;
roleLabel: string;
}
