How to process each letter of text using JavaScript ?
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:
Last Updated :
16 Aug, 2021
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