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Javascript 如何在react native中使用foreach inside Alert.Alert_Javascript_Reactjs_For Loop_React Native_Alert - Fatal编程技术网

Javascript 如何在react native中使用foreach inside Alert.Alert

Javascript 如何在react native中使用foreach inside Alert.Alert,javascript,reactjs,for-loop,react-native,alert,Javascript,Reactjs,For Loop,React Native,Alert,请使用.map功能而不是.forEach.forEach不返回任何值,因此您只需在数组中传递undefined 考虑下面的例子 function openmodal(modalarray) { return Alert.alert( "Alert Title", "My Alert Msg", [ modalarray.forEach(element => { "{text: element, onPress: () => co

请使用
.map
功能而不是
.forEach
.forEach
不返回任何值,因此您只需在数组中传递
undefined

考虑下面的例子

function openmodal(modalarray) {
  return Alert.alert(
    "Alert Title",
    "My Alert Msg",
    [
      modalarray.forEach(element => {
        "{text: element, onPress: () => console.log('button press)},";
      })
    ],
    { cancelable: false }
  );
}
希望这会有帮助

试试看:

function openmodal(modalarray) {
  return Alert.alert(
    "Alert Title",
    "My Alert Msg",
    [
      ...modalarray.map(element =>
        ({text: element, onPress: () => console.log('button press')}))
    ],
    { cancelable: false }
  );
}

有没有一种方法可以使用嵌套映射??我的意思是如何将一个映射嵌套在另一个映射中??是的,如果数组元素是数组本身,则可以嵌套,如
[[1,2],[3,4]
function openmodal(modalarray) {
  return Alert.alert(
    "Alert Title",
    "My Alert Msg",
    modalarray.map(element => ({
      text: element,
      onPress: () => console.log('button press')
    })),
    { cancelable: false }
  );
}