Question

How to use substring() to get sub string a subset of a string between one index and another in JavaScript

Answer 1

// str.substring(indexStart[, indexEnd])

var s = "abcdefghijklmnop";

document.write(s.substring(-3, 1) + "<br />");
document.write(s.substring(-3, 2) + "<br />");
document.write(s.substring(-3, 3) + "<br />");
document.write(s.substring(-30, 2) + "<br />");
document.write(s.substring(-2) + "<br />");
document.write(s.substring(1) + "<br />");
document.write(s.substring(0) + "<br />");


/*
run:

a
ab
abc
ab
abcdefghijklmnop
bcdefghijklmnop
abcdefghijklmnop

*/

 

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Answer 2

// str.substring(indexStart[, indexEnd])

var s = "abcdefghijklmnop";

document.write(s.substring(0, 1) + "<br />");
document.write(s.substring(1, 1) + "<br />");
document.write(s.substring(0, 2) + "<br />");
document.write(s.substring(0, 3) + "<br />");
document.write(s.substring(1, 2) + "<br />"); // b
document.write(s.substring(1, 3) + "<br />");
document.write(s.substring(3, 5) + "<br />"); // de
document.write(s.substring(10, 3) + "<br />"); 
document.write(s.substring(10, 4) + "<br />"); 
document.write(s.substring(10, 5) + "<br />"); 
document.write(s.substring(10, 13) + "<br />"); // klm
document.write(s.substring(30, 2) + "<br />");


/*
run:

a

ab
abc
b
bc
de
defghij
efghij
fghij
klm
cdefghijklmnop

*/

 

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