String: Difference between revisions
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In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable.<ref>https://en.wikipedia.org/wiki/String_(computer_science)</ref>. | In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable.<ref>https://en.wikipedia.org/wiki/String_(computer_science)</ref>. | ||
Because strings are a sequence of characters, we can usually select them in the same way we can select elements from an array. For example: | |||
<syntaxhighlight lang="python3"> | |||
myString = 'Hello World' | |||
print(mystring[2]) | |||
# this program would output the letter l (L) . | |||
</syntaxhighlight> | |||
Revision as of 06:21, 7 August 2017
Programming basics[1]
In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable.[2].
Because strings are a sequence of characters, we can usually select them in the same way we can select elements from an array. For example:
myString = 'Hello World'
print(mystring[2])
# this program would output the letter l (L) .
Example[edit]
Here we encounter some different syntax rules. Programming languages define strings differently. Please do pay attention to the quotation marks, double quotation marks, and triple quotation marks.
PHP[edit]
<?php
$a = 1234.65; // decimal number
$a = -1234.54; // a negative number
?>
Python[edit]
- Single quotes: 'allows embedded "double" quotes'
- Double quotes: "allows embedded 'single' quotes".
- Triple quoted: Three single quotes, """Three double quotes"""
Triple quoted strings may span multiple lines - all associated whitespace will be included in the string literal.[3]
myString = 'Hello World'
Javascript[edit]
// decimal number:
var a = 1234.65;
// a negative number:
var a = -1234.65;
Do you understand this?[edit]
Standards[edit]
- Define the terms: variable, constant, operator, object.