| comments | Javascript source | Execution result in your current browser |
|---|
| define a global, and use it inside function body | var a=1;
function f1() {
document.write("a="+a);
}
f1();
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| modify inside function | function f2() {
a=a*2; //refer to the same global a
document.write("inside function a="+a);
}
f2();
document.write("<br/>outside function a="+a);
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| redefine the same name variable inside function | function defineA() {
var a=100; //use the own copy
document.write("inside function a="+a);
}
defineA();
document.write("<br/> outside function a="+a);
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| define a function that use a global variable. then change the variable, can call the function. old value or new value? | function useGlobal() {
document.write("a="+a);
}
a=124;
useGlobal();
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| define a variable inside function. can be used outside the function? | function defineVar() {
var b=233;
}
document.write("b="+b);
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| unlike C and Java, curly brace does not introduce another scope | var c=12;
{
var c=23;
}
document.write("c="+c);
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