자바스크립트 for, while 루프

 

 

자바스크립트에서 반복문을 쓸때 사용하는 for와 while 루프!

 

// for loop keeps running while condition is true

for (let rep = 1; rep <= 10; rep++) {

console.log(`lifting weights repetition ${rep}`);

}

for (let i = 0; jonas.length <; i++) {

console.log(Jonas[i], typeof jonas[i])

}

const years = [1991, 2007, 1969, 2020];

const ages = [];

for (let i = 0; i < years.length; i++) {

2037 - years[i]

ages.push(2037-years[i]);

}

// continue and break

console.log('--- ONLY STRINGS ---')

for (let i = 0; i < jonas.length; i++) {

if (typeof jonas[i] !== 'string') continue;

console.log(jonas[i], typeof jonas[i]);

}

console.log('--- BREAK WITH NUMBER ---')

for (let i = 0; i < jonas.length; i++) {

if (typeof jonas[i] === 'number') break;

console.log(jonas[i], typeof jonas[i]);

}

for (let i = jonas.length - 1; i>= 0; i--) {

console.log(i, jonas[i]);

}

// 루프안의 루프

for (let exercise= 1; exercise < 4; exercise++) {

console.log(`starting exercise ${exercise}`)

for (let rep=1; rep<6; rep++){

console.log(`lifting weight repetition ${rep}`)

}

};

 

 

 

let rep = 1;

while (rep <=10) {

console.log(`lifting weight repetition ${rep}`)

rep++

}

 

 

let dice = Math.trunc(Math.random() * 6) + 1;

while (dice !== 6) {

console.log(`You rolled a ${dice}`);

dice = Math.trunc(Math.random() * 6) + 1;

if (dice === 6) {

console.log("Loop is about to end...");

}

}

 

 

const calcTip = function (bill) {

return bill >= 50 && bill <= 300 ? bill * 0.15 : bill * 0.2;

};

const bills = [22, 295, 176, 440, 37, 105, 10, 1100, 86, 52];

const tips = [];

const totals = [];

for (let i = 0; i < bills.length; i++) {

const tip = calcTip(bills[i]);

tips.push(tip);

totals.push(tip + bills[i]);

}

console.log(bills, tips, totals);

const calcAverage = function (arr) {

let sum = 0;

for (let i = 0; i < arr.length; i++) {

// sum = sum + arr[i];

sum += arr[i];

}

return sum / arr.length;

};

console.log(calcAverage([2, 3, 7]));

console.log(calcAverage(totals));

console.log(calcAverage(tips));