JavaScript – Strings manipulation
Statements:
// single or double quote are allowed var carname="Volvo XC60"; var carname='Volvo XC60'; // Quotes inside a string var answer="It's alright"; var answer="He is called 'Johnny'"; var answer='He is called "Johnny"'; var answer='It\'s alright'; var answer="He is called \"Johnny\"";
Properties and Methods:
// ###################################################################
// Add HTML text tags
// ###################################################################
var str="Hello world!";
document.write(str.bold() + "<br>"); // the result is <b>Hello world!</b>
document.write(str.blink() + "<br>") // the result is <blink>Hello world!</blink> Firefox support only
document.write(str.big() + "<br>"); // the result is <big>Hello world!</big>
document.write(str.anchor() + "<br>"); // the result is <a name="undefined">Hello world!</a>
document.write(str.fontcolor() + "<br>"); // the result is <font color="undefined">Hello world!</font>
document.write(str.fontsize() + "<br>"); // the result is <font size="undefined">Hello world!</font>
document.write(str.italics() + "<br>"); // the result is <i>Hello world!</i>
document.write(str.small() + "<br>"); // the result is <small>Hello world!</small>
document.write(str.strike() + "<br>"); // the result is <strike>Hello world!</strike>
document.write(str.sub() + "<br>"); // the result is <sub>Hello world!</sub> - pedice
document.write(str.sup() + "<br>"); // the result is <sup>Hello world!</sup> - apice
// ###################################################################
// Character position - index of a character
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// You can access each character in a string with its position
// The first index position is 0
var character=carname[0]; // the result is c
var character=carname[1]; // the result is a
var str = "HELLO WORLD";
var res = str.charAt(0) // The result is H - the character at index 0
var str = "HELLO WORLD";
var n = str.charCodeAt(0) // The result is 72 - the unicode of character at index 0
var str="Hello World";
var n=str.indexOf("World"); // n stores 7 - the position of W from the first letter
var n=str.lastIndexOf("World"); // n stores 5 - the position of W from the last letter
// n stores -1 if the specified text is not found
// Return position of the string you are searching
var str = "Visit Luce Digitale!";
var n = str.search("Luce"); // the result is 6 (the first index value is 0)
// ###################################################################
// String Lenght
// ###################################################################
var txt = "Hello World!";
var x = txt.length; // x stores 12
// ###################################################################
// Find a string in string
// ###################################################################
// Maching Content
var str="Hello world!";
document.write(str.match("world") + "<br>"); // the result is world
document.write(str.match("World") + "<br>"); // the result is null
document.write(str.match("world!")); // the result is world!
// Compare two strings in the current locale:
var str1 = "ab";
var str2 = "cd";
var n = str1.localeCompare(str2); // the result is -1, str1 is sorted before str2
// ###################################################################
// Manipulate Content
// ###################################################################
// Replace Content
str="Please visit Microsoft!"
var n=str.replace("Microsoft","Luce Digitale"); // the result is - Please visit Luce Digitale! -
// Join two strings
var str1 = "Hello ";
var str2 = "world!";
var res = str1.concat(str2); // the result is Hello world!
// Convert a Unicode number into a character
var res = String.fromCharCode(65); // the result is A
// Slice
var str = "Hello world!";
var res = str.slice(1,5); // the result is - ello -
// Split -> Great to write databases in a flat txt file!
var str = "How are you doing today?";
var res = str.split(" "); // the result is - How,are,you,doing,today? -
// Extract a part of a string
var str = "Hello world!";
var res = str.substr(1,4) // the result is - ello -
// Remove whitespace from both sides of a string
var str = " Hello World! "; // The value is - Hello World! -
alert(str.trim()); // The value is -Hello World!-
// ###################################################################
// Upper Case - Lower Case
// ###################################################################
var txt="Hello World!"; // String
var txt1=txt.toUpperCase(); // result is HELLO WORLD!
var txt2=txt.toLowerCase(); // result is hello world!
// ###################################################################
// Convert a number to a string
// ###################################################################
var num = 15;
var n = num.toString(); // the result is 15, the value turs into a string now!
// ###################################################################
// Convert a string to a number
// ###################################################################
var a = "1.45kg";
var n = parseFloat(a) // the result is 1.45, the value turns into a number now!
// ###################################################################
// Convert a String to an Array - removing the commas, spaces, pipe
// ###################################################################
var str="a,b,c,d,e,f";
var n=str.split(",");
alert(n[1]); // result is b! (the array index start at 0)
// Complete List
txt.split(","); // Split on commas -> Great to read databases from a flat txt file!
txt.split(" "); // Split on spaces
txt.split("|"); // Split on pipe
Tips: to Write “databases” in flat .txt file you can use:
// Remove commas
var str="a,b,c,d,e,f";
var n=str.split(",");
alert(n[1]); // result is b! (the array index start at 0)
// Insert commas
// Split
var str = "How are you doing today?";
var res = str.split(" "); // the result is - How,are,you,doing,today? -
Special Character in strings manipulation:
\' single quote \" double quote \\ backslash \n new line \r carriage return \t tab \b backspace \f form feed
