ts: for循环 Element implicitly has an ‘any’ type because index expression is not of type ‘number’.

// beofre 
const props = defineProps({
    
    
  columns: {
    
    
    type: Array,
  }
})
function dataChange(data) {
    
    
  for (let item in props.columns) {
    
    
    // item报错：Element implicitly has an 'any' type because index expression is not of type 'number'.
    const key = props.columns[item].key;
    props.columns[item].visible = !data.includes(key);
  }
}

解决办法：

• 报错信息 应该是由于 columns 元素类型不确定， 因此遍历变量item类型也不能确定
• 找到 props.columns 的具体类型 或者 any似乎也可以

// after 使用any类型
function dataChange(data:any[]) {
    
    
  let columns = props.columns as Array<any>
  for (let item in columns) {
    
    
    const key = (columns[item]).key;
    columns[item].visible = !data.includes(key);
  }
}

// after 使用 column 真实类型
interface ColumnsElement {
    
    
  key: number,
  value: string,
  visible: boolean
}
const props = defineProps({
    
    
  columns: {
    
    
    type: Array<ColumnsElement>,
  }
})
function dataChange(data:any[]) {
    
    
  let columns = props.columns as Array<ColumnsElement>
  for (let item in columns) {
    
    
    const key = (columns[item]).key;
    columns[item].visible = !data.includes(key);
  }
}