JavaScript String Methods
| Method | Description |
|---|---|
| charAt() | Returns the character at the specified index (position) |
| Returns the Unicode of the character at the specified index | |
| concat() | Joins two or more strings, and returns a new joined strings |
| endsWith() | Checks whether a string ends with specified string/characters |
| fromCharCode() | Converts Unicode values to characters |
| includes() | Checks whether a string contains the specified string/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 |
| repeat() | Returns a new string with a specified number of copies of an existing string |
| 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 |
| startsWith() | Checks whether a string begins with specified characters |
| 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 |
All string methods return a new value. They do not change the original variable.
Number Methods
Method Description 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) toFixed(x) Formats a number with x numbers of digits after the decimal point toLocaleString() Converts a number into a string, based on the locale settings toPrecision(x) Formats a number to x length toString() Converts a number to a string valueOf() Returns the primitive value of a number
| Method | Description |
|---|---|
| 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) | |
| toFixed(x) | Formats a number with x numbers of digits after the decimal point |
| toLocaleString() | Converts a number into a string, based on the locale settings |
| toPrecision(x) | Formats a number to x length |
| toString() | Converts a number to a string |
| valueOf() | Returns the primitive value of a number |
Method Description 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 entries() Returns a key/value pair Array Iteration Object every() Checks if every element in an array pass a test fill() Fill the elements in an arrsay 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 from() Creates an array from an object includes() Check if an array contains the specified 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 keys() Returns a Array Iteration Object, containing the keys of the original array 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
| Method | Description |
|---|---|
| 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 |
| entries() | Returns a key/value pair Array Iteration Object |
| every() | Checks if every element in an array pass a test |
| fill() | Fill the elements in an arrsay 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 |
| from() | Creates an array from an object |
| includes() | Check if an array contains the specified 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 |
| keys() | Returns a Array Iteration Object, containing the keys of the original array |
| 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 |
JS Math Object Methods
Method Description abs(x) Returns the absolute value of x acos(x) Returns the arccosine of x, in radians acosh(x) Returns the hyperbolic arccosine of x asin(x) Returns the arcsine of x, in radians asinh(x) Returns the hyperbolic arcsine of x 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 atanh(x) Returns the hyperbolic arctangent of x cbrt(x) Returns the cubic root of x ceil(x) Returns x, rounded upwards to the nearest integer cos(x) Returns the cosine of x (x is in radians) cosh(x) Returns the hyperbolic cosine of x exp(x) Returns the value of Ex floor(x) 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) sinh(x) Returns the hyperbolic sine of x sqrt(x) Returns the square root of x tan(x) Returns the tangent of an angle tanh(x) Returns the hyperbolic tangent of a number trunc(x)
| Method | Description |
|---|---|
| abs(x) | Returns the absolute value of x |
| acos(x) | Returns the arccosine of x, in radians |
| acosh(x) | Returns the hyperbolic arccosine of x |
| asin(x) | Returns the arcsine of x, in radians |
| asinh(x) | Returns the hyperbolic arcsine of x |
| 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 |
| atanh(x) | Returns the hyperbolic arctangent of x |
| cbrt(x) | Returns the cubic root of x |
| ceil(x) | Returns x, rounded upwards to the nearest integer |
| cos(x) | Returns the cosine of x (x is in radians) |
| cosh(x) | Returns the hyperbolic cosine of x |
| exp(x) | Returns the value of Ex |
| floor(x) | |
| 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) |
| sinh(x) | Returns the hyperbolic sine of x |
| sqrt(x) | Returns the square root of x |
| tan(x) | Returns the tangent of an angle |
| tanh(x) | Returns the hyperbolic tangent of a number |
| trunc(x) |
JSON Methods
Method Description parse() Parses a JSON string and returns a JavaScript object stringify() Convert a JavaScript object to a JSON string
| Method | Description |
|---|---|
| parse() | Parses a JSON string and returns a JavaScript object |
| stringify() | Convert a JavaScript object to a JSON string |
Valid Data Types
In JSON, values must be one of the following data types:
- a string
- a number
- an object (containing valid JSON values)
- an array
- a boolean
- null
In JSON, values must be one of the following data types:
- a string
- a number
- an object (containing valid JSON values)
- an array
- a boolean
- null
Method Description getDate() Returns the day of the month (from 1-31) getDay() Returns the day of the week (from 0-6) getFullYear() Returns the year 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, and a specified date 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 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) getYear() . Use the getFullYear() method instead now() Returns the number of milliseconds since midnight Jan 1, 1970 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 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 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 setYear() . Use the setFullYear() method instead toDateString() Converts the date portion of a Date object into a readable string toGMTString() . Use the toUTCString() method instead 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
| Method | Description |
|---|---|
| getDate() | Returns the day of the month (from 1-31) |
| getDay() | Returns the day of the week (from 0-6) |
| getFullYear() | Returns the year |
| 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, and a specified date |
| 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 |
| 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) |
| getYear() | . Use the getFullYear() method instead |
| now() | Returns the number of milliseconds since midnight Jan 1, 1970 |
| 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 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 |
| 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 |
| setYear() | . Use the setFullYear() method instead |
| toDateString() | Converts the date portion of a Date object into a readable string |
| toGMTString() | . Use the toUTCString() method instead |
| 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 |
String HTML Wrapper Methods
The HTML wrapper methods return the string wrapped inside the appropriate HTML tag.
