2019-11-05 02:09:40 -01:00
---
id: 5d792534408c5be896b0a46e
2020-08-25 02:19:45 -07:00
title: Part 37
2019-11-05 02:09:40 -01:00
challengeType: 0
---
2020-11-27 19:02:05 +01:00
# --description--
2019-11-05 02:09:40 -01:00
2019-12-09 19:37:02 +09:00
The `hasOwnProperty` method checks if a key exists in an object. So `spreadsheetFunctions.hasOwnProperty("")` would return `true` , but replacing `""` with anything else would make it return `false` .
2019-11-05 02:09:40 -01:00
Chain `hasOwnProperty` to `spreadsheetFunctions` to check if the `fn.toLowerCase()` key exists in `spreadsheetFunctions` .
2020-11-27 19:02:05 +01:00
# --hints--
2019-11-05 02:09:40 -01:00
2020-11-27 19:02:05 +01:00
See description above for instructions.
2019-11-05 02:09:40 -01:00
2020-11-27 19:02:05 +01:00
```js
assert(
code
.replace(/\s/g, '')
.includes(
'returnstr2.replace(regex,(match,fn,args)=>spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()))'
)
);
```
2019-11-05 02:09:40 -01:00
2020-11-27 19:02:05 +01:00
# --seed--
2019-11-05 02:09:40 -01:00
2020-11-27 19:02:05 +01:00
## --before-user-code--
2019-11-05 02:09:40 -01:00
2020-11-27 19:02:05 +01:00
```html
<!DOCTYPE html>
< html lang = "en" >
< head >
< meta charset = "UTF-8" >
< title > Spreadsheet< / title >
< style >
#container {
display: grid;
grid-template-columns: 50px repeat(10, 200px);
grid-template-rows: repeat(11, 30px);
}
.label {
background-color: lightgray;
text-align: center;
vertical-align: middle;
line-height: 30px;
}
< / style >
< / head >
< body >
< div id = "container" >
< div > < / div >
< / div >
2019-11-05 02:09:40 -01:00
```
2020-11-27 19:02:05 +01:00
## --after-user-code--
2019-11-05 02:09:40 -01:00
2020-11-27 19:02:05 +01:00
```html
< / body >
< / html >
```
2019-11-05 02:09:40 -01:00
2020-11-27 19:02:05 +01:00
## --seed-contents--
2019-11-05 02:09:40 -01:00
```html
< script >
const infixToFunction = {
"+": (x, y) => x + y,
"-": (x, y) => x - y,
"*": (x, y) => x * y,
"/": (x, y) => x / y
};
const infixEval = (str, regex) =>
str.replace(regex, (_, arg1, fn, arg2) =>
infixToFunction[fn ](parseFloat(arg1 ), parseFloat(arg2))
);
const highPrecedence = str => {
const regex = /([0-9.]+)([*\/])([0-9.]+)/;
const str2 = infixEval(str, regex);
return str === str2 ? str : highPrecedence(str2);
};
const spreadsheetFunctions = {
"": x => x
};
const applyFn = str => {
const noHigh = highPrecedence(str);
const infix = /([0-9.]+)([+-])([0-9.]+)/;
const str2 = infixEval(noHigh, infix);
const regex = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
const toNumberList = args => args.split(",").map(parseFloat);
const applyFunction = (fn, args) =>
spreadsheetFunctions[fn.toLowerCase() ](toNumberList(args ));
return str2.replace(regex, (match, fn, args) => spreadsheetFunctions);
}
< / script >
```
2020-11-27 19:02:05 +01:00
# --solutions--
2019-11-05 02:09:40 -01:00
```html
< script >
const infixToFunction = {
"+": (x, y) => x + y,
"-": (x, y) => x - y,
"*": (x, y) => x * y,
"/": (x, y) => x / y
};
const infixEval = (str, regex) =>
str.replace(regex, (_, arg1, fn, arg2) =>
infixToFunction[fn ](parseFloat(arg1 ), parseFloat(arg2))
);
const highPrecedence = str => {
const regex = /([0-9.]+)([*\/])([0-9.]+)/;
const str2 = infixEval(str, regex);
return str === str2 ? str : highPrecedence(str2);
};
const spreadsheetFunctions = {
"": x => x
};
const applyFn = str => {
const noHigh = highPrecedence(str);
const infix = /([0-9.]+)([+-])([0-9.]+)/;
const str2 = infixEval(noHigh, infix);
const regex = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
const toNumberList = args => args.split(",").map(parseFloat);
const applyFunction = (fn, args) =>
spreadsheetFunctions[fn.toLowerCase() ](toNumberList(args ));
return str2.replace(
regex,
(match, fn, args) =>
spreadsheetFunctions.hasOwnProperty(fn.toLowerCase())
);
}
< / script >
```
