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Substring

Finds a string in a larger string.

Syntax

substring(String, List, Integer)

Description

Given a string s, a list of strings {s1,...,sk}, and a positive integer n, searches si in ss starting from the nn-th char. If more than one sj appears in the original string, only the first appearance is returned. If the find ends with no matches, failed is returned. The output is a list with two elements: an integer with the position of the string and the string sis_i.

programming.substring1.calc.png

Given a string ss and a list of strings {s1,...,sk}\lbrace s_1, ..., s_k \rbrace, searches sis_i in ss. If more than one sjs_j appears in the original string, only the first appearance is returned. If the find ends with no matches, failed is returned. The output is a list with two elements: an integer with the position of the string and the string sis_i.

programming.substring2.calc.png

Note

The math content is converted to MathML inside the corresponding string if there is a special character or any mathematical expression in the string. For instance, if the kernel receives s = "2 <math><mo>.</mo></math> 17", the substring function won't return the expected value. In this case, you need to include the string previously through the code editor.