root
10 lines
314 B
JavaScript
10 lines
314 B
JavaScript
export const substring = (input, start, stop, reverse) => {
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if (start >= stop || input.length < stop || /[^\u0000-\u007f]/.test(input)) {
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return null;
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}
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if (!reverse) {
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return input.substring(start, stop);
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}
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return input.substring(input.length - stop, input.length - start);
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};
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