javascript - React-native 数组检查值是否存在

Question

如何检查ticketId是否已经插入到数组中？

这是代码:

state = { myState: [], status: 0, limit: 5 };

  selected(ticketId) {
  if (this.state.status < this.state.limit) { 
    this.state.myState.push({ id: ticketId }); //what ever i chose get inserted
    this.state.status++;
    this.setState({ status: this.state.status }); 
    //console.log('here', this.state.status);
  } else {
    console.log('3'); //check if condition meet
  }
 }

如果 ticketId 已经插入并触发警报，我如何创建条件检查 myState 数组？

Answer 1

当您存储为对象 {id:value} 时，最好改用“every”。

state = { myState: [], status: 0, limit: 5 };

selected(ticketId) {
   if (this.state.status < this.state.limit ) { 
      if(this.state.myState.every((item) => item.id !== ticketId)){
        this.state.myState.push({ id: ticketId }); //what ever i chose get inserted
        this.state.status++;
        this.setState({ status: this.state.status }); 
      //console.log('here', this.state.status);
     }
   } else {
   console.log('3'); //check if condition meet
   } 
}