Given a string and the task is to process it character by character.
- JavaScript String toUpperCase() Method: This method converts a string to uppercase letters.
Syntax:
string.toUpperCase()
- Parameters: This method accepts single parameter str which is required. It specifies the string to be searched.
Return Value: It returns a string denoting the value of a string converted to uppercase.
- JavaScript String charAt() Method: This method returns the character at the passed index in a string. The index of characters starts from 0.
Syntax:
string.charAt(index)
- Parameters: This method accepts single parameter index which is required. It specifies the integer representing the index of the character to return.
Return Value: It returns a string, denoting the character at the passed index, or an empty string if the index number is invalid.
Example 1: This example processes the string letter by letter using for loop and converts each letter to uppercase separately.
html
<!DOCTYPE HTML> < html > < head > < title > How to process each character of text </ title > </ head > < body style = "text-align:center;" > < h1 style = "color:green;" > GeeksForGeeks </ h1 > < p id = "GFG_UP" style = "font-size: 15px; font-weight: bold;" > </ p > < button onclick = "gfg_Run()" > check </ button > < p id = "GFG_DOWN" style = "color:green; font-size: 20px; font-weight: bold;" > </ p > < script > var el_up = document.getElementById("GFG_UP"); var el_down = document.getElementById("GFG_DOWN"); var str = "This is String"; el_up.innerHTML = "String = '"+str + "'"; function gfg_Run() { var str_Upper = ""; for (var i = 0; i < str.length ; i++) { str_Upper += str.charAt(i).toUpperCase(); } el_down.innerHTML = str_Upper ; } </script> </ body > </ html > |
Output:
- Before clicking on the button:
- After clicking on the button:
Example 2: This example processes the string letter by letter using for in loop and alerts each letter separately.
html
<!DOCTYPE HTML> < html > < head > < title > How to process each letter of text </ title > </ head > < body style = "text-align:center;" > < h1 style = "color:green;" > GeeksForGeeks </ h1 > < p id = "GFG_UP" style = "font-size: 15px; font-weight: bold;" > </ p > < button onclick = "gfg_Run()" > check </ button > < script > var el_up = document.getElementById("GFG_UP"); var str = "str"; el_up.innerHTML = "String = '" + str + "'"; function gfg_Run() { for (var i in str) { alert(" character = "+str.charAt(i)); } } </ script > </ body > </ html > |
Output:
- Before clicking on the button:
- After clicking on the button: