Input a Javascript expression or statement and press enter
js>
Javascript Cheat Sheet
  • arithmetic: + - * / %←means remainder. There's no ^ for exponentiation!
  • math functions: Math.sin( ), Math.cos( ), Math.log( ), Math.exp( ), Math.sqrt( ), Math.floor( )
  • math constants: Math.PI, Math.E
  • variables: define like var x; or var x = 0;. Assign like x = x + 1;
  • semicolon: use ; to terminate statements, e.g. var x; x = 17;
  • string literals: "hi" or 'hi' or 'I said "hi", right?'
  • escaping: within a string literal, \" for ", \' for ', \\ for \, \n for newline
  • string operations: "a" + "b"ab, "foobar"[3]b, "foobar".length6
  • strings and ASCII:
  • typeof: returns type name as a string, e.g. typeof(43*7)Number
  • conversions: String-to-Number Number("42"), Number-to-String String(42)
  • alert: display pop-up window with text, e.g. alert("Hello World!");
  • prompt: get string from user via pop-up window, e.g var n = prompt("Enter your name");