program		Error Messages
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20	var x = "Welcome to SY110";

JavaScript Cheat Sheet

• line comments: // ... is a line comment, text on the rest of the line is ignored
• block comments: /* ... */ is a block comment, text between the open /* and close */ is ignored. Allows multiple line comments.
• arithmetic: + - * / %←means remainder. ^ is not for exponentiation!
• math functions: Math.sin( ), Math.cos( ), Math.log( ), Math.exp( ), Math.sqrt( ), Math.floor( )
• math constants: Math.PI, Math.E, (Math Object reference)
• 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".length → 6
• strings and ASCII: string.length, string.charCodeAt[index] (String Object reference)
• 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");