basic.js

function echo(str, b) {
    println(['echo', str])
    return b
}
function testAnd() {
    println(['jfkd'])
    println(['========== testAnd 1 =========='])
    var b = echo('1', true) && echo('1', true)
    println(['========== testAnd 2 =========='])
    b = echo('0', false) && echo('1', true)
}
function testOr() {
    println(['========== testOr 1 =========='])
    var b = echo('0', false) || echo('0', false)
    println(['========== testOr 1 =========='])
    b = echo('1', true) || echo('0', false)
}
function printPrime(n) {
    println(['========== printPrime =========='])
    for (var i = 2; i < n; ++i) {
        var flag = true
        for (var j = 2; j <= i / 2; ++j) {
            if (i % j == 0) {
                flag = false
                break
            }
        }
        if (flag) println([i])
    }
    println([])
}
function factorial(n) {
    if (n <= 1) return 1
    return n * factorial(n - 1)
}
function printFeb1() {
    println(['========== printFeb1 =========='])
    var i = 1 
    var j = 1
    while (i < 100) {
        println([j])
        var t = i + j
        j = i
        i = t
    }
    println([])
}
function feb2(n) {
    // it's hard to print function name, so...
    if (n <= 2) { return 1 }
    return feb2(n - 1) + feb2(n - 2)
}
function printFeb2() {
    println(['========== printFeb2 =========='])
    var i = 1
    while (i <= 10) {
        println([feb2(i)])
        i = i + 1
    }
    println([])
}
function print9x9() {
    println(['========== print9x9 =========='])
    for (var i = 1; i <= 9; ++i) {
        for (var j = 1; j <= i; ++j) {
            print([format('{0}x{1}={2,-2} ', [j, i, i * j])])
        }
        println([])
    }
}
function perform() {
    println(['========== perform =========='])
    var start = clock()
    for (var i = 0; i < 1000000; ++i);
    println(['loop 1000000 times: ', clock() - start])
}
function main()  {
    // test for comment
    testAnd() // test for comment too
    testOr()
    printPrime(30)
    println(['factorial', 10, factorial(10)])
    printFeb1()
    printFeb2()
    print9x9()
    perform()
    println(['15-3*(2*2+(7-2)) = ', 15-3*(2*2+(7-2))])
}
main()