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| 1 | +/** |
| 2 | + * 1st case |
| 3 | + * input: '?foo=hello&bar=world' |
| 4 | + output: { |
| 5 | + foo: 'hello', |
| 6 | + bar: 'world' |
| 7 | + } |
| 8 | + |
| 9 | + * 2nd case |
| 10 | + * input: '?' (if there is no query after ?) |
| 11 | + output: should be an empty object like this 👉🏻 {} |
| 12 | + |
| 13 | + * 3rd case |
| 14 | + * input: '?foo=hello&bar=world&baz' (if there is no equal sign) |
| 15 | + output: { |
| 16 | + foo: 'hello', |
| 17 | + bar: 'world', |
| 18 | + baz: 'true' // send by default true as string |
| 19 | + } |
| 20 | + |
| 21 | + * 4th case |
| 22 | + * input: '?foo=hello&bar=world&baz&foo=again' (if there is value with the same key, have to save values as array item) |
| 23 | + output: { |
| 24 | + foo: ['hello', 'again], // save value as array item whick belong to save key |
| 25 | + bar: 'world', |
| 26 | + baz: 'true' |
| 27 | +} |
| 28 | + |
| 29 | + */ |
| 30 | + |
| 31 | +const formatQueryString = (str) => { |
| 32 | + // strip off ? and then split by & |
| 33 | + const query = str.slice(1).split("&"); |
| 34 | + const resObj = {}; |
| 35 | + |
| 36 | + // iterate through key value pairs, split on = , and save in res object as key value |
| 37 | + for (const pair of query) { |
| 38 | + let [key, value] = pair.split("="); |
| 39 | + |
| 40 | + // check if key truthy else send empty object (2nd case) |
| 41 | + if (key) { |
| 42 | + value = value || "true"; // checking value is truthy or undefined else befault 'true' value (3rd case) |
| 43 | + |
| 44 | + // if there is value with the same key, have to save values as array item (4th case) |
| 45 | + resObj[key] = resObj[key] |
| 46 | + ? typeof resObj[key] === "string" |
| 47 | + ? [resObj[key], value] |
| 48 | + : [...resObj[key], value] |
| 49 | + : value; |
| 50 | + |
| 51 | + // resObj[key] = resObj[key] |
| 52 | + // ? Array.isArray(resObj[key]) |
| 53 | + // ? [...resObj[key], value] |
| 54 | + // : [resObj[key], value] |
| 55 | + // : value; |
| 56 | + } |
| 57 | + } |
| 58 | + |
| 59 | + return resObj; |
| 60 | +}; |
| 61 | + |
| 62 | +// console.log("1st case: ", formatQueryString("?foo=hello&bar=world"), { |
| 63 | +// foo: 'hello', |
| 64 | +// bar: 'world' |
| 65 | +// }); |
| 66 | +// console.log("2nd case: ", formatQueryString("?"), {}); // if there is no query after ? |
| 67 | +// console.log("3rd case: ", formatQueryString("?foo=hello&bar=world&baz"), { |
| 68 | +// foo: "hello", |
| 69 | +// bar: "world", |
| 70 | +// baz: "true", |
| 71 | +// }); |
| 72 | + |
| 73 | +/*console.log( |
| 74 | + "4th case: ", |
| 75 | + formatQueryString("?foo=hello&bar=world&baz&foo=again&foo=ok&bar=again&baz&dummy&data=earth"), |
| 76 | + { |
| 77 | + foo: [ 'hello', 'again', 'ok' ], |
| 78 | + bar: [ 'world', 'again' ], |
| 79 | + baz: [ 'true', 'true' ], |
| 80 | + dummy: 'true', |
| 81 | + data: 'earth' |
| 82 | + } |
| 83 | +); */ |
| 84 | + |
| 85 | +// test case |
| 86 | +console.log("4th case: ", formatQueryString("?foo=hello&foo"), { |
| 87 | + foo: ["hello", "true"], |
| 88 | +}); |
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