Article From:https://segmentfault.com/q/1010000012145622
Question:
The WeChat applet has a function requirement to transfer the string to the object. It can be implemented quickly by using the eval method.
This is probably the process.
var name = 'bb[0]'; //name It is a variable, assuming that its value is'bb[0]', and the value that may also be passed is'aa[0] or bb[1]'.Var data = {"AA": [[111], "222"], "BB": [[333], "444"];The value of //data is fixedVar newData = Eval ('data.'+name); / / method 1The result of //console.log (newData) is 333VarJsonStr = JSON.stringify (data);Var newData = (New Function ("var temp =" + jsonStr + "; return)Temp.'+ name)) (); / / method 2The result of //console.log (newData) is 333Later found that the original JS functions that were banned after updating the applet: new Function, Eval and Generator. That means the previous methods can’t be used.
In addition to the 2 above, what is the way to get the correct result of newData?
Answer 0:
Shouldn’t it be the _.at of lodash? Without making wheels, lodash is ready for you.
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };
_.at(object, ['a[0].b.c', 'a[1]']);
// => [3, 4]Jab the official document _.at
Answer 1:
You can write this
hold var name = 'bb[0]';====> Through regular transformationvar test = ['bb', '0']
ThennewData = data[test[0]].test[1]
Answer 2:
function trans(data, name) {
let reg = /\[?[^\[\]]+\]?/g
let reg2 = /\]/
let names = name.match(reg)
if (names.length) {
names = names.map(item => reg2.test(item) ? item.slice(1, -1) : item)
return names.reduce((sum, cur) => sum[cur], data)
}
}
var data = {"aa":["111","222"],"bb":["333","444"]};
var name = 'bb[0]';
trans(data, name)Answer 3:
var data = {"aa":["111","222"],"bb":["333","444"]};
name = 'bb[0]';
function getNewData(data, name){
var prefix = name.split('[')[0],
endStr = name.split('[')[1];
var index = endStr.split(']')[0];
return data[prefix][index];
}
var newName = getNewData(data, name);
console.log(newName); // 333‘
Answer 4:
data['bb']['0']Answer 5:
A regular match is all right
function aaa(json,str){
var b = str.replace(/(\S)\[([0-9]+)\]/,'$1,$2').split(',');
return json[b[0]][b[1]];
}
var newData = aaa(data,name);
console.log(newData);
Link of this Article:
The problem of transferring the JS string to the object