How?! by 384.cz

function u(t) {

c.width=1920 // clear the canvas
for(i=0;i<9;i++)
x.fillRect(400+i*100+S(t)*300,400,50,200) // draw 50x200 rects

} // 122/140

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    u(t) is called 60 times per second.
    t: Elapsed time in seconds.
    S: Shorthand for Math.sin.
    C: Shorthand for Math.cos.
    T: Shorthand for Math.tan.
    R: Function that generates rgba-strings, usage ex.: R(255, 255, 255, 0.5)
    c: A 1920x1080 canvas.
    x: A 2D context for that canvas.

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384.cz

function u(t) {

throw 052

Dec 19 2023 6:15 PM UTC

}// 9/140

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How?!

Show more comments…
u/danny@hille.dk

prefixing any number with 0, and javascript interpret it as octodecimal (base 8) jist like prefixing with 0x nd javascript interpret it as hexadecimal (base 16)
u/Odog8

100% worst js feature
u/danny@hille.dk

It's a C language feature that bleed in Java, and from Java into javascript
u/Odog8

ah, didnt know that, neat. Still frustrating imo
u/New_Core

there is 0o for octal.. if use just 0 and accidently have a 8 or 9, it becomes a normal decimal while 0o will throw an error. as said before, you have 0b = binary 0o = octal 0x = hexa
u/rodrigo.siqueira

oh no, 078 throws "78" and 077 throws "63".
u/neimad

077/078 is not a really a gotcha. It seems to follow Javascript's patterns for type coercion. Some numbers can evaluate as octal numbers, and some can't. If a string starts with 0 and contains only numbers 0 through 7, then it is evaluated as octal. If the string starts with 0 and has any number above 7 (not octal), then it evaluates as decimal. It's not a mystery, it actually makes some sense even if octal in Javascript is not normally used.
u/tomxor

On the rare occasion when you need to set file permissions from JS you will finally appreciate it :D


      u(t) is called 60 times per second.
      t: elapsed time in seconds.
      c: A 1920x1080 canvas.
      x: A 2D context for that canvas.
      S: Math.sin
      C: Math.cos
      T: Math.tan
      R: Generates rgba-strings, ex.: R(255, 255, 255, 0.5)

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