Web Development_Sec6_Java secriptvvvvv.pdf

Web Development_Sec6_Java secriptvvvvv.pdf

• 1.
  Web Development
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  JavaScript • To declarevariable in javascript use: 1) var Ex: var x=5; 2) let Ex: let x=5; 3) const Ex: const y=7;
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  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.
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  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”.
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  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”.
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  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”.
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  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”
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  JavaScript String Methods •To convert string to UpperCase(): 6) toUpperCase() method: will be used to convert string from lower to upper case.
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  JavaScript String Methods •To convert string to lower case(): 7) toLowerCase() method: will be used to convert string from Upper to lower case.
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  JavaScript String Methods 8)concat() method : joins two or more strings
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  JavaScript String Methods 9)trim() method : used to remove white spaces from both sides of a string.
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  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.
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  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.