Web Development_Sec6_Java secriptvvvvv.pdf
- 2. JavaScript • To declare variable in javascript use: 1) var Ex: var x=5; 2) let Ex: let x=5; 3) const Ex: const y=7;
- 3. JavaScript String Methods • String methods help you to work with strings. 1) The length property returns the length of a string. • To extract part of string use slice(), substring(), substr() functions.
- 4. JavaScript String Methods 2) slice(start, end): extracts a part of a string and returns the extracted part in a new string. • This example slices out a portion of a string from position 7 to position 12 (13-1) and the output will be “Banana”.
- 5. JavaScript String Methods 3) substring(start, end): is similar to slice() and the difference is that substring() cannot accept negative indexes. • This example substring a portion of a string from position 7 to position 12 (13-1) and the output will be “Banana”.
- 6. JavaScript String Methods 4) substr(start, length): is similar to slice() and the difference is that the second parameter specifies the length of the extracted part. • This example will print from position 7 to and count 6 characters after it and the output will be “Banana”.
- 7. JavaScript String Methods • Replacing String content: 5) replace() method : replaces a specified value with another value in a string. • This example will replace “Microsoft” with “W3schools”
- 8. JavaScript String Methods • To convert string to UpperCase(): 6) toUpperCase() method: will be used to convert string from lower to upper case.
- 9. JavaScript String Methods • To convert string to lower case(): 7) toLowerCase() method: will be used to convert string from Upper to lower case.
- 10. JavaScript String Methods 8) concat() method : joins two or more strings
- 11. JavaScript String Methods 9) trim() method : used to remove white spaces from both sides of a string.
- 12. JavaScript String Methods 10) indexof() method : return index of (position) of the first occurrence of specified text in string. •The result of this code will be 7.
- 13. JavaScript String Methods 11) lastindexof() method : return index of (position) of the last occurrence of specified text in string. • The result of this code will be 21.