mandytang / 170509

Javascript Beginner Lab

17-05-09

什麼是 Camel 命名法? lower camel case: firstName; upper camel case: FirstName var = varible, string, boolean = true, false Number("122.5") convert to number; Number("122.5 years") output NAN; string.substr(start, length); string.indexOf(searchvalue, start) Operators https://www.w3schools.com/jsref/jsref_operators.asp var y = 5; var x = ++y; //Prefix Increment //++y //x=y document.write = y ==> 6 document.write = x ==> 6

var y = 5; var x = --y; //Prefix Decrement //--y //x=y document.write = y ==> 4 document.write = x ==> 4

var y = 5; var x = y++; //Postfix Increment //x=y //y++ document.write = y ==> 6 document.write = x ==> 5

var y = 5; var x = y--; //Postfix Decrement //x=y //y-- document.write = y ==> 4 document.write = x ==> 5

if (condition) { block of code to be executed if the condition is true } else { block of code to be executed if the condition is false }

difference b/w continue & break

for (statement 1; statement 2; statement 3) { code block to be executed } Statement 1 is executed before the loop (the code block) starts. i = 0;
Statement 2 defines the condition for running the loop (the code block). i < 5; Statement 3 is executed each time after the loop (the code block) has been executed. i++