29:null 2a:["$","title",null,{"children":"Homework 1 — Variables, data types, and expressions in TypeScript | Emmanuel Moneda | Observable"}] 2f:[] 2d:{"id":"048c368b54ca9194","slug":"homework-1-variables-data-types-and-expressions-in-type-script","title":"Homework 1 — Variables, data types, and expressions in TypeScript","thumbnail":"7fd2b33f7bf0ab046ae3d7f02b4b86676527a8ee00b173c0de6957961893e4c4","access_level":"public","create_time":"$D2026-09-10T06:33:57.027Z","update_time":"$D2026-09-16T22:03:35.564Z","view_time":null,"first_public_time":"$D2026-09-16T17:46:00.939Z","has_unpublished_edits":null,"fork":true,"stars":0,"starred":false,"owner":{"type":"team","id":"072af1879e1ca85e","login":"xander","name":"Emmanuel Moneda","avatar_url":null,"tier":"starter_2024"},"version":279,"publish_version":279,"role":null,"authored":false,"authors":[{"type":"individual","id":"c4658abd9d943864","login":"xander","name":"Emmanuel Moneda","avatar_url":null,"tier":null}],"members":[{"type":"team","id":"072af1879e1ca85e","login":"xander","name":"Emmanuel Moneda","avatar_url":null,"tier":"starter_2024","role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":null,"type":"notebook","body":{"title":"Homework 1 — Variables, data types, and expressions in TypeScript","cells":[{"id":1,"value":"# Homework 1 — Variables, data types, and expressions in TypeScript","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":8,"value":"In this lab you'll get some experience declaring and using variables. You'll also use existing commands to perform more complex computations.\n\nAs you work through this notebook, look for items marked with ${flag()}. These indicate place where you need to complete something.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":11,"value":"## Part 1: Variables and Data Types","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":12,"value":"Consider the expressions listed below. Recall that an *expression* is anything that can evaluated to a *value.*\n\nYour task in this part is to **declare** and **initialize** variables to hold each of the values below.\nFor each variable, give it a name and the appropriate *data type.*\n\nWrite each answer in a new TypeScript cell. The first one is done for you already as an example.\n\nHere are the expressions:\n\n1. `10`\n2. `Math.PI`\n3. `\"what am i\"`\n4. `\"false\"`\n5. `true`\n6. `[true, false, false]`\n7. `Math.pow(2, 5)`\n8. `\"TypeScript\".toLowerCase()`\n9. `0`\n10. `-273.15`\n11. `1_000_000`\n12. `\"Hello, world!\"`\n13. `''`\n14. `\"123\"`\n15. `\"true\"`\n16. `false`\n17. `` `Result: \\${((5 * 12) - (48 / 2) + Math.pow(2, 3))}` ``\n18. `10 > 3`\n19. `5 === 5`\n20. `\"abc\".length`\n21. `Math.sqrt(16)`\n22. `Math.round(2.8)`\n23. `\"typescript\".toUpperCase()`","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":14,"value":"const ten: number = 10;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":17,"value":"$${flag()} Work on the rest of the expressions in new cells below this one.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":33,"value":"const mathpi: number = Math.PI;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":38,"value":"const whatAmI: string = \"what am i\";","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":39,"value":"const strFalse: string = \"false\";","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":40,"value":"const boolTrue: boolean = true;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":41,"value":"const boolArray: boolean[] = [true, false, false];","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":42,"value":"const powResult: number = Math.pow(2, 5);","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":43,"value":"const lowerCased: string = \"TypeScript\".toLowerCase();","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":44,"value":"const zero: number = 0;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":45,"value":"const negativeTemp: number = -273.15;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":46,"value":"const oneMillion: number = 1_000_000;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":47,"value":"const helloWorld: string = \"Hello, world!\";","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":48,"value":"const emptyString: string = '';","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":49,"value":"const string123: string = \"123\";","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":50,"value":"const stringTrue: string = \"true\";","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":51,"value":"const boolFalse: boolean = false;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":52,"value":"const templateResult: string = `Result: ${((5 * 12) - (48 / 2) + Math.pow(2, 3))}`;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":53,"value":"const greaterThan: boolean = 10 > 3;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":54,"value":"const strictEqual: boolean = 5 === 5;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":55,"value":"const abcLength: number = \"abc\".length;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":56,"value":"const sqrtResult: number = Math.sqrt(16);","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":57,"value":"const roundResult: number = Math.round(2.8);","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":58,"value":"const upperCased: string = \"typescript\".toUpperCase();","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":18,"value":"## Part 2: Boolean operators","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":19,"value":"### Part 2.1\n\n${flag()} Consider the following expressions. For each one, think about what its value will be and write it next to the expression in the cell below. If you want to test out an expression, feel free to create a new TypeScript cell to see its value.\n","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":35,"value":"\n\n1. `7 > 0` true\n2. `true && (10 > 2)` true\n3. `(3 < 1) || (4 >= 4)` true\n4. `!(2 * 2 === 5)` true\n5. `\"Is 8 greater than 12? \" + (8 > 12)` false","pinned":true,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":20,"value":"### Part 2.2\n\nSuppose you have a variable named `score`, representing a student's numerical score on an exam. The cell below defines a _slider input_ that lets you try out different values for `score` (the value of `score` will change automatically as you drag the slider back and forth).","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":23,"value":"const score: number = view(Inputs.range([0, 100], { step: 1 }))","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":26,"value":"_We'll play with user inputs more later in the term!_","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":22,"value":"Use this `score` variable for the next two questions.\n\n1. ${flag()} Write a **ternary expression** that tells us if `score` is even or odd. Your expression should \"fit\" inside the `evenOrOdd` variable described below. `evenOrOdd` should have the value `\"even\"` if `score` is even, and `\"odd\"` if `score` is odd.\n\n_Replace the blank below with your own code. The `RuntimeError` will disappear once you do that._","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":28,"value":"// Write your code in this cell\nconst evenOrOdd: boolean = score % 2 === 0 ? \"even\" : \"odd\";;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":27,"value":"2. ${flag()} Write an expression to decide the student's letter grade based on their numerical score, according to the following rules:\n\n* If the score is greater than or equal to 90, the grade should be `\"A\"`,\n* Otherwise, if the score is greater than or equal to 80, the grade should be `\"B\"`\n* Otherwise, if the score is greater than or equal to 70, the grade should be `\"C\"`\n* Otherwise, the score should be `\"D/F\"`\n\nYou will need to write a *compound expression* that combines several ternary expressions to accomplish this. I suggest that you begin by drawing a \"decision tree\" like we have discussed in class.\n\n_Replace the blank below with your own code. The `RuntimeError` will disappear once you do that._","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":30,"value":"const grade: string = score >= 90 ? \"A\" : score >= 80 ? \"B\" : score >= 70 ? \"C\" : \"D/F\";;","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":31,"value":"## Submission","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":32,"value":"In the right-hand column, click the Settings wheel. A menu will open on the right. Click on **Make unlisted**.\n\n\"Unlisted\" means that your notebook is accessible to anyone with the link, but won't show up in people's search results.\n\nAfter clicking **Make unlisted**, copy the URL of your notebook, and submit that URL in Canvas.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":10,"value":"---\n\n## Appendix\n\n_Don't change anything below this line. It may cause parts of the notebook to not work properly. But feel free to explore or ask me what any of it means!_","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":4,"value":"import { flag, stylesheet } from 'observable:@ayaankazerouni/utils'","pinned":true,"hidden":false,"mode":"ts","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":37,"value":"","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W2f","stdlib":"2","titling":"auto"}} 2e:"$2d:body"