Uvod
U sklopu samog JavaScript-a postoje ugradjeni objekti sa svojim svojstvima i metodama, namenjeni da olakšaju programiranje.
- Array
- Math
- Date
- Function
Pored navedenih objekata postoje još i objekti čija imena su ista kao imena prostih primitiva (samo sa velikim početnim slovom):
- String
- Number
Ovi objekti sa “opremljeni” metodama potrebnim za rad sa odgovarajućim tipom podataka i zamišljeni su da olakšaju rad sa primitivnim tipovima. Kada se pojavi potreba za operacijom nad takvim primitivnim tipom, kompajler automatski “obmotava” prost tip u njegov “parnjak” objekat nakon čega su dostupne sve metode ugradjenog objekta.
U ovom članku sam želeo da pregledno okupim na jednom mestu sve metode i svojstva objekata ugradjenih u javascript-u.
“String” kao objekat
Matode koje mogu da se primene na string objekat:
Metode String objekta
| Metoda objekta | Opis |
|---|---|
| charAt() | Returns the character at the specified index (position) |
| charCodeAt() | Returns the Unicode of the character at the specified index |
| concat() | Joins two or more strings, and returns a new joined strings |
| fromCharCode() | Converts Unicode values to characters |
| indexOf() | Returns the position of the first found occurrence of a specified value in a string |
| lastIndexOf() | Returns the position of the last found occurrence of a specified value in a string |
| localeCompare() | Compares two strings in the current locale |
| match() | Searches a string for a match against a regular expression, and returns the matches |
| replace() | Searches a string for a specified value, or a regular expression, and returns a new string where the specified values are replaced |
| search() | Searches a string for a specified value, or regular expression, and returns the position of the match |
| slice() | Extracts a part of a string and returns a new string |
| split() | Splits a string into an array of substrings |
| substr() | Extracts the characters from a string, beginning at a specified start position, and through the specified number of character |
| substring() | Extracts the characters from a string, between two specified indices |
| toLocaleLowerCase() | Converts a string to lowercase letters, according to the host’s locale |
| toLocaleUpperCase() | Converts a string to uppercase letters, according to the host’s locale |
| toLowerCase() | Converts a string to lowercase letters |
| toString() | Returns the value of a String object |
| toUpperCase() | Converts a string to uppercase letters |
| trim() | Removes whitespace from both ends of a string |
| valueOf() | Returns the primitive value of a String object |
Metode koje obavijaju “string” HTML tagom
Sledeće metode vraćaju string obavijen sa HTML tagom (eventualno nekim HTML atributom).
| Metoda objekta | Opis |
|---|---|
| anchor() | Creates an anchor |
| big() | Displays a string using a big font |
| blink() | Displays a blinking string |
| bold() | Displays a string in bold |
| fixed() | Displays a string using a fixed-pitch font |
| fontcolor() | Displays a string using a specified color |
| fontsize() | Displays a string using a specified size |
| italics() | Displays a string in italic |
| link() | Displays a string as a hyperlink |
| small() | Displays a string using a small font |
| strike() | Displays a string with a strikethrough |
| sub() | Displays a string as subscript text |
| sup() | Displays a string as superscript text |
“Number” kao objekat
Number je objekat koji ima ugradjene sledeće metode:
| Metod | Opis metoda |
|---|---|
| isFinite() | Checks whether a value is a finite number |
| isInteger() | Checks whether a value is an integer |
| isNaN() | Checks whether a value is Number.NaN |
| isSafeInteger() | Checks whether a value is a safe integer |
| toExponential(x) | Converts a number into an exponential notation |
| toFixed(x) | Formats a number with x numbers of digits after the decimal point |
| toPrecision(x) | Formats a number to x length |
| toString() | Converts a number to a string |
| valueOf() | Returns the primitive value of a number |
“Function” kao objekat
Function je objekat koji ima ugradjene sledeće metode:
| Metod | Opis metoda |
|---|---|
| Function.prototype.apply() | Ova metoda daje izabranoj funkciji željeno značenje ključne reči “this”, stim što odmah poziva funkciju (eng. invoke). Kroz prvi argument definiše na koji objekat će ukazivati ključna reč this, dok su ostali argumenti koji se prosledjuju kroz array, podaci potrebni početnoj funkciji. |
| Function.prototype.bind() | Function.prototype.bind()Ova metoda daje izabranoj funkciji željeno značenje ključne reči “this”. Kroz prvi argument definiše na koji objekat će ukazivati ključna reč this, dok su ostali argumenti koji se prosledjuju kao lista argumenata, podaci potrebni početnoj funkciji. |
| Function.prototype.call() | Function.prototype.call()Ova metoda daje izabranoj funkciji željeno značenje ključne reči “this”, stim što odmah poziva funkciju (eng. invoke). Kroz prvi argument definiše na koji objekat će ukazivati ključna reč this, dok su ostali argumenti koji se prosledjuju kao lista argumenata, podaci potrebni početnoj funkciji. |
Array objekat
Metode koje se mogu primeniti na objekat array su sledeće:
| Metoda | Opis |
|---|---|
| concat() | Joins two or more arrays, and returns a copy of the joined arrays |
| copyWithin() | Copies array elements within the array, to and from specified positions |
| every() | Checks if every element in an array pass a test |
| fill() | Fill the elements in an array with a static value |
| filter() | Creates a new array with every element in an array that pass a test |
| find() | Returns the value of the first element in an array that pass a test |
| findIndex() | Returns the index of the first element in an array that pass a test |
| forEach() | Calls a function for each array element |
| indexOf() | Search the array for an element and returns its position |
| isArray() | Checks whether an object is an array |
| join() | Joins all elements of an array into a string |
| lastIndexOf() | Search the array for an element, starting at the end, and returns its position |
| map() | Creates a new array with the result of calling a function for each array element |
| pop() | Removes the last element of an array, and returns that element |
| push() | Adds new elements to the end of an array, and returns the new length |
| reduce() | Reduce the values of an array to a single value (going left-to-right) |
| reduceRight() | Reduce the values of an array to a single value (going right-to-left) |
| reverse() | Reverses the order of the elements in an array |
| shift() | Removes the first element of an array, and returns that element |
| slice() | Selects a part of an array, and returns the new array |
| some() | Checks if any of the elements in an array pass a test |
| sort() | Sorts the elements of an array |
| splice() | Adds/Removes elements from an array |
| toString() | Converts an array to a string, and returns the result |
| unshift() | Adds new elements to the beginning of an array, and returns the new length |
| valueOf() | Returns the primitive value of an array |
Math objekat
Svojstva Math objekta
Svojstva Math objekta vraćaju neku od poznatih matematičkih konstanti:
| Svojstvo objekta | Opis |
|---|---|
| E | Returns Euler’s number (approx. 2.718) |
| LN2 | Returns the natural logarithm of 2 (approx. 0.693) |
| LN10 | Returns the natural logarithm of 10 (approx. 2.302) |
| LOG2E | Returns the base-2 logarithm of E (approx. 1.442) |
| LOG10E | Returns the base-10 logarithm of E (approx. 0.434) |
| PI | Returns PI (approx. 3.14) |
| SQRT1_2 | Returns the square root of 1/2 (approx. 0.707) |
| SQRT2 | Returns the square root of 2 (approx. 1.414) |
Math metode
Metode Math objekta uzimaju broj kao atribut a vraćaju rezultat neke matematičke operacije nad tim brojem:
| Metoda objekta | Opis |
|---|---|
| abs(x) | Returns the absolute value of x |
| acos(x) | Returns the arccosine of x, in radians |
| asin(x) | Returns the arcsine of x, in radians |
| atan(x) | Returns the arctangent of x as a numeric value between -PI/2 and PI/2 radians |
| atan2(y,x) | Returns the arctangent of the quotient of its arguments |
| ceil(x) | Returns x, rounded upwards to the nearest integer |
| cos(x) | Returns the cosine of x (x is in radians) |
| exp(x) | Returns the value of Ex |
| floor(x) | Returns x, rounded downwards to the nearest integer |
| log(x) | Returns the natural logarithm (base E) of x |
| max(x,y,z,…,n) | Returns the number with the highest value |
| min(x,y,z,…,n) | Returns the number with the lowest value |
| pow(x,y) | Returns the value of x to the power of y |
| random() | Returns a random number between 0 and 1 |
| round(x) | Rounds x to the nearest integer |
| sin(x) | Returns the sine of x (x is in radians) |
| sqrt(x) | Returns the square root of x |
| tan(x) | Returns the tangent of an angle |
Datum objekat
Date je objekat u javascriptu koji je zadužen za datum i vreme a metode koje mogu da se primene na taj objekat su sledeće:
| Metoda objekta | Opis |
|---|---|
| getDate() | Returns the day of the month (from 1-31) |
| getDay() | Returns the day of the week (from 0-6) |
| getFullYear() | Returns the year (four digits) |
| getHours() | Returns the hour (from 0-23) |
| getMilliseconds() | Returns the milliseconds (from 0-999) |
| getMinutes() | Returns the minutes (from 0-59) |
| getMonth() | Returns the month (from 0-11) |
| getSeconds() | Returns the seconds (from 0-59) |
| getTime() | Returns the number of milliseconds since midnight Jan 1, 1970 |
| getTimezoneOffset() | Returns the time difference between UTC time and local time, in minutes |
| getUTCDate() | Returns the day of the month, according to universal time (from 1-31) |
| getUTCDay() | Returns the day of the week, according to universal time (from 0-6) |
| getUTCFullYear() | Returns the year, according to universal time (four digits) |
| getUTCHours() | Returns the hour, according to universal time (from 0-23) |
| getUTCMilliseconds() | Returns the milliseconds, according to universal time (from 0-999) |
| getUTCMinutes() | Returns the minutes, according to universal time (from 0-59) |
| getUTCMonth() | Returns the month, according to universal time (from 0-11) |
| getUTCSeconds() | Returns the seconds, according to universal time (from 0-59) |
| parse() | Parses a date string and returns the number of milliseconds since January 1, 1970 |
| setDate() | Sets the day of the month of a date object |
| setFullYear() | Sets the year (four digits) of a date object |
| setHours() | Sets the hour of a date object |
| setMilliseconds() | Sets the milliseconds of a date object |
| setMinutes() | Set the minutes of a date object |
| setMonth() | Sets the month of a date object |
| setSeconds() | Sets the seconds of a date object |
| setTime() | Sets a date to a specified number of milliseconds after/before January 1, 1970 |
| setUTCDate() | Sets the day of the month of a date object, according to universal time |
| setUTCFullYear() | Sets the year of a date object, according to universal time (four digits) |
| setUTCHours() | Sets the hour of a date object, according to universal time |
| setUTCMilliseconds() | Sets the milliseconds of a date object, according to universal time |
| setUTCMinutes() | Set the minutes of a date object, according to universal time |
| setUTCMonth() | Sets the month of a date object, according to universal time |
| setUTCSeconds() | Set the seconds of a date object, according to universal time |
| toDateString() | Converts the date portion of a Date object into a readable string |
| toISOString() | Returns the date as a string, using the ISO standard |
| toJSON() | Returns the date as a string, formatted as a JSON date |
| toLocaleDateString() | Returns the date portion of a Date object as a string, using locale conventions |
| toLocaleTimeString() | Returns the time portion of a Date object as a string, using locale conventions |
| toLocaleString() | Converts a Date object to a string, using locale conventions |
| toString() | Converts a Date object to a string |
| toTimeString() | Converts the time portion of a Date object to a string |
| toUTCString() | Converts a Date object to a string, according to universal time |
| UTC() | Returns the number of milliseconds in a date since midnight of January 1, 1970, according to UTC time |
| valueOf() | Returns the primitive value of a Date object |