我如何在 javascript 中访问函数外部的变量

Question

我想在函数外访问 const newdata    function updateFields(response) {        $("#FIELDSET").removeProp('disabled');        const parser = new DOMParser();        const xmlDoc = parser.parseFromString(response, "text/xml");        const data = xmlDoc.getElementsByTagName("responses")[0].innerHTML;        const rdata = data.split('//')[0]        const payload = data.split(':1:1,')            .map(x => x.split('='))            .reduce((obj, x) => {                obj[x[0].replace(/\./g, '_')] = x[1];                return obj;            }, {})        const newdat="string";        CO_CODE=payload.CO_CODE.split(':1:1')[0]        const {AMOUNT, INT_RATE, TERM, FREQUENCY, REP_START_DATE, CUSTOMER_ID, INSTALMENT} = payload;    }

Answer 1

如果newdat不是特定于——或特别依赖于——你的updateFields方法，你可以在updateFields范围之外维护它；每当updateFields被调用时更新它。

let newdat = '';

function updateFields() {

    // ...

    newdat = "string";

    // ...

}

function someOtherFunction() {

    console.log( 'newdat =' + newdat ); // would log the current value of `newdat` when called

}

let newdat = '';

function updateFields() {

  newdat = "string";

}

function someOtherFunction() {

  console.log('newdat = ' + newdat); // would log the current value of `newdat` when called

}

updateFields();

someOtherFunction();