Essentials of Javascript - Cultural View

JavaScript syntax 35
For loop
The syntax of the JavaScript for loop is as follows:
or
for (initial;condition;loop statement) {
}
/*
*/
statements will be executed every time
the for{} loop cycles, while the
condition is satisfied
for (initial;condition;loop statement) // one statement
For ... in loop
The syntax of the JavaScript For ... in loop is as follows:
for (var property_name in some_object) {
}
//statements using some_object[property_name];
• Iterates through all enumerable properties of an object.
• Sources differ on whether this is usable for arrays [5] .
• There are differences between the various web browsers with regard to which properties will be reflected with the
for...in loop statement. In theory, this is controlled by an internal state property defined by the ECMAscript
standard called "DontEnum", but in practice each browser returns a slightly different set of properties during
introspection. It is usefull to test given property using if (some_object.hasOwnProperty(property_name)) { ... }
While loop
The syntax of the JavaScript while loop is as follows:
while (condition) {
}
statement1;
statement2;
statement3;
...
Do ... while loop
The syntax of the JavaScript do ... while loop is as follows:
do {
statement1;
statement2;
statement3;
...
} while (condition);