DOM Working with data
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1) Get the name from the number
- You can obtain data from the server using a fetch call.
- In these examples you will be getting data from https://progzoo.net/worldl.json this is a list of 195 countries in json format
- The program snippet shows the name of country 42.
- Change it so it shows the name of country 50.
- See if you can find your country.
Input
xxxxxxxxxx
fetch('/worldl.json')
.then((r)=>r.json())
.then((r)=>{
let tgt = r[42];
document.body.innerHTML = tgt.name;
});
Output
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let tgt = r[42]; document.body.innerHTML = tgt.name; });
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let tgt = r[50]; document.body.innerHTML = tgt.name; });
Each country has a bunch of data associated, for example:
area: 330803 capital: "Kuala Lumpur" continent: "Asia" flag: "//upload.wikimedia.org/wikipedia/commons/6/66/Flag_of_Malaysia.svg" gdp: 304726000000 id: 102 name: "Malaysia" population: 30177000 tld: ".my"
2) Show the population
Alter your code so that the output matches the model answer.
Input
xxxxxxxxxx
fetch('/worldl.json')
.then((r)=>r.json())
.then((r)=>{
let tgt = r[102];
document.body.innerHTML =
`<div>${tgt.name}</div>`;
});
Output
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let tgt = r[102]; document.body.innerHTML = `<div>${tgt.name}</div>`; });
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let tgt = r[102]; document.body.innerHTML = `<div>${tgt.name}, ${tgt.population}</div>`; });
3) Include image
Include three div elements and an img for country 151. Use
style='width:100px;'
for the imgInput
xxxxxxxxxx
fetch('/worldl.json')
.then((r)=>r.json())
.then((r)=>{
let tgt = r[151];
document.body.innerHTML =
`<div>${tgt.name}, ${tgt.capital}</div>`;
});
Output
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let tgt = r[151]; document.body.innerHTML = `<div>${tgt.name}, ${tgt.capital}</div>`; });
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let tgt = r[151]; document.body.innerHTML = ` <div>Name: ${tgt.name}</div> <div>Capital: ${tgt.capital}</div> <div>Population: ${tgt.population}</div> <img src='${tgt.flag}' style='width:100px'/> `; });
4) Output in a table
Input
xxxxxxxxxx
fetch('/worldl.json')
.then((r)=>r.json())
.then((r)=>{
let tgt = r[172];
document.body.innerHTML =
`<div>${tgt.name}, ${tgt.capital}</div>`;
});
Output
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let tgt = r[172]; document.body.innerHTML = `<div>${tgt.name}, ${tgt.capital}</div>`; });
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let tgt = r[172]; document.body.innerHTML = ` <table> <tr><th>Name</th><td>${tgt.name}</td</tr> <tr><th>Continent</th><td>${tgt.continent}</td</tr> <tr><th>Capital</th><td>${tgt.capital}</td</tr> <tr><th>Population</th><td>${tgt.population}</td</tr> </table> `; });
5) Format numbers
For country 184. Use .toLocaleString() to format numbers better. Show the GDP in billions, include $ symbol as GDP is given in US dollars
Input
xxxxxxxxxx
fetch('/worldl.json')
.then((r)=>r.json())
.then((r)=>{
let tgt = r[184];
document.body.innerHTML =
`<div>${tgt.population.toLocaleString()}</div>`;
});
Output
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let tgt = r[184]; document.body.innerHTML = `<div>${tgt.population.toLocaleString()}</div>`; });
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let tgt = r[184]; document.body.innerHTML = ` <table> <tr><th>Name</th><td>${tgt.name}</td></tr> <tr><th>Continent</th><td>${tgt.continent}</td></tr> <tr><th>Capital</th><td>${tgt.capital}</td></tr> <tr><th>Population</th><td>${tgt.population.toLocaleString('en')}</td></tr> <tr><th>GDP</th><td>${tgt.gdp.toLocaleString('en')} billion</td></tr> </table> `; });
Working with lists
In the following questions you must look at the list of the countries to work out the answer.
6) Biggest Country in the World
Show the name of the country with the largest population.
Input
xxxxxxxxxx
fetch('/worldl.json')
.then((r)=>r.json())
.then((r)=>{
let biggest = 0;
for(let i = 0; i<r.length; i++){
if (r[i].area > r[biggest].area){
biggest = i;
}
}
document.body.innerHTML =
`<div>${r[biggest].name}</div>`;
});
Output
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let biggest = 0; for(let i = 0; i<r.length; i++){ if (r[i].area > r[biggest].area){ biggest = i; } } document.body.innerHTML = `<div>${r[biggest].name}</div>`; });
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let biggest = 0; for(let i = 0; i<r.length; i++){ if (r[i].population > r[biggest].population){ biggest = i; } } document.body.innerHTML = `<div>${r[biggest].name}</div>`; });
7) Total population
Show the total population of the world.
Input
1
Output
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ let acc = 0; for(let i = 0; i<r.length; i++){ acc += r[i].population } document.body.innerHTML = `<div>${acc}</div>`; });
8) Countries bigger than 1000000
Show list of countries with an area of more than 1 million square kilometers.
Input
1
Output
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ document.body.innerHTML = r.filter(r=>r.area>1000000) .map(r=>`<div>${r.name}</div>`) .join(''); });
9) Countries in Europe
Show list of countries where the continent is Europe.
Input
1
Output
fetch('/worldl.json') .then((r)=>r.json()) .then((r)=>{ document.body.innerHTML = r.filter(r=>r.continent === 'Europe') .map(r=>`<div>${r.name}</div>`) .join(''); });