6.9 KiB
6.9 KiB
id, title, challengeType, isBeta
| id | title | challengeType | isBeta |
|---|---|---|---|
| 5d792537b6cadae0f4b0cda1 | Part 094 | 0 | true |
Description
The slice method takes two arguments. It extracts characters from the string from the index specified by the first argument up to (but not including) the second argument. The index starts at 0.
Use the slice method to log the first two letters of value to the console.
Instructions
Tests
tests:
- text: See description above for instructions.
testString: assert(code.replace(/\s/g, "").includes("console.log(value.slice(0,2))"));
Challenge Seed
<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()) ? applyFunction(fn, args) : match
);
};
const range = (start, end) =>
start > end ? [] : [start].concat(range(start + 1, end));
const charRange = (start, end) =>
range(start.charCodeAt(0), end.charCodeAt(0)).map(x =>
String.fromCharCode(x)
);
const evalFormula = x => {
const rangeRegex = /([A-J])([1-9][0-9]?):([A-J])([1-9][0-9]?)/gi;
const rangeFromString = (n1, n2) => range(parseInt(n1), parseInt(n2));
const elemValue = n => c => document.getElementById(c + n).value;
const addChars = c1 => c2 => n => charRange(c1, c2).map(elemValue(n));
const varRangeExpanded = x.replace(rangeRegex, (_, c1, n1, c2, n2) =>
rangeFromString(n1, n2).map(addChars(c1)(c2))
);
const varRegex = /[A-J][1-9][0-9]?/gi;
const varExpanded = varRangeExpanded.replace(
varRegex,
match => document.getElementById(match.toUpperCase()).value
);
const functionExpanded = applyFn(varExpanded);
return functionExpanded === x
? functionExpanded
: evalFormula(functionExpanded);
};
window.onload = () => {
const container = document.getElementById("container");
const createLabel = name => {
const label = document.createElement("div");
label.className = "label";
label.textContent = name;
container.appendChild(label);
};
const letters = charRange("A", "J");
letters.forEach(createLabel);
range(1, 99).forEach(x => {
createLabel(x);
letters.forEach(y => {
const input = document.createElement("input");
input.type = "text";
input.id = y + x;
input.onchange = update;
container.appendChild(input);
});
});
};
const update = event => {
const element = event.target;
const value = element.value.replace(/\s/g, "");
if (!value.includes(element.id) && value[0] === "=") {}
};
</script>
Before Test
<!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>
After Test
</body>
</html>
Solution
<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()) ? applyFunction(fn, args) : match
);
};
const range = (start, end) =>
start > end ? [] : [start].concat(range(start + 1, end));
const charRange = (start, end) =>
range(start.charCodeAt(0), end.charCodeAt(0)).map(x =>
String.fromCharCode(x)
);
const evalFormula = x => {
const rangeRegex = /([A-J])([1-9][0-9]?):([A-J])([1-9][0-9]?)/gi;
const rangeFromString = (n1, n2) => range(parseInt(n1), parseInt(n2));
const elemValue = n => c => document.getElementById(c + n).value;
const addChars = c1 => c2 => n => charRange(c1, c2).map(elemValue(n));
const varRangeExpanded = x.replace(rangeRegex, (_, c1, n1, c2, n2) =>
rangeFromString(n1, n2).map(addChars(c1)(c2))
);
const varRegex = /[A-J][1-9][0-9]?/gi;
const varExpanded = varRangeExpanded.replace(
varRegex,
match => document.getElementById(match.toUpperCase()).value
);
const functionExpanded = applyFn(varExpanded);
return functionExpanded === x
? functionExpanded
: evalFormula(functionExpanded);
};
window.onload = () => {
const container = document.getElementById("container");
const createLabel = name => {
const label = document.createElement("div");
label.className = "label";
label.textContent = name;
container.appendChild(label);
};
const letters = charRange("A", "J");
letters.forEach(createLabel);
range(1, 99).forEach(x => {
createLabel(x);
letters.forEach(y => {
const input = document.createElement("input");
input.type = "text";
input.id = y + x;
input.onchange = update;
container.appendChild(input);
});
});
};
const update = event => {
const element = event.target;
const value = element.value.replace(/\s/g, "");
if (!value.includes(element.id) && value[0] === "=") {
console.log(value.slice(0, 2));
}
};
</script>